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To display the test results for the Time Domain Reflectometry (TDR) cable diagnostics, use the showcable-diagnosticstdrcommand in privileged EXEC mode.
show cable-diagnostics tdr interface interface interface-number
interface interface |
Specifies the interface type; valid values arefastethernet and gigabitethernet. |
interface-number |
Module and port number. |
This command has no default settings.
Privileged EXEC
The showcable-diagnosticstdr command is supported on specific modules. See the Release Notes for Cisco IOS Release 12.2 SX on the Catalyst 6500 and Cisco 7600 Supervisor Engine 720, Superivsor Engine 32, and Supervisor Engine 2 for the list of the modules that support TDR.
In the event of an open or shorted cable, the accuracy of length of where the cable is open or shorted is plus or minus 2 meters.
The pair length can be displayed in meters (m), centimeters (cm), or kilometers (km).
If the TDR test has not been run on the port, the following message is displayed:
TDR test was never run on Gi2/12
This example shows how to display the information about the TDR test:
Router# show cable-diagnostics tdr interface gigabitethernet 8/1 TDR test last run on: February 25 11:18:31 Interface Speed Pair Cable length Distance to fault Channel Pair status --------- ----- ---- ------------------- ------------------- ------- ------------ Gi8/1 1000 1-2 1 +/- 6 m N/A Pair B Terminated 3-4 1 +/- 6 m N/A Pair A Terminated 5-6 1 +/- 6 m N/A Pair C Terminated 7-8 1 +/- 6 m N/A Pair D Terminated
The table below describes the fields in the showcable-diagnosticstdrcommand output.
Command |
Description |
---|---|
clear cable-diagnostics tdr |
Clears a specific interface or clear all interfaces that support TDR. |
test cable-diagnostics |
Tests the condition of 10-Gigabit Ethernet links or copper cables on 48-port 10/100/1000 BASE-T modules. |
To display EtherChannel information for a channel, use the showetherchannel command in privileged EXEC mode.
show etherchannel [channel-group] { port-channel | brief | detail | summary | port | load-balance }
show etherchannel [channel-group] { port-channel | brief | detail | summary | port | load-balance | protocol } [expression]
channel -group |
(Optional) Number of the channel group. If you do not specify a value for the channel -group argument, all channel groups are displayed. |
port -channel |
Displays port channel information. |
brief |
Displays a summary of EtherChannel information. |
detail |
Displays detailed EtherChannel information. |
summary |
Displays a one-line summary per channel group. |
port |
Displays EtherChannel port information. |
load -balance |
Displays load-balance information. |
protocol |
Displays the enabled protocol. |
expression |
(Optional) Expression in the output to use as a reference point. |
Privileged EXEC (#)
Release |
Modification |
---|---|
12.0(7)XE |
This command was introduced on Cisco Catalyst 6000 family switches. |
12.1(3a)E3 |
This command was modified. The number of valid values for the channel -group argument were changed. |
12.1(5c)EX |
This command was modified. The number of valid values for the channel-group argument were changed. |
12.2(2)XT |
This command was modified to support switchport creation on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers. |
12.2(14)SX |
This command was implemented on the Supervisor Engine 720. |
12.2(17a)SX1 |
This command was modified. The output of the showetherchannelload-balance command was changed to include IPv6 information. The display was changed to include Multiprotocol Label Switching (MPLS) information. |
12.2(17d)SXB |
This command was modified to support the Supervisor Engine 2. |
12.2(8)T |
This command was modified to support switchport creation. |
12.2(33)SXH |
This command was modified. The output of the showetherchannelport-channel and the showetherchanneldetailcommands was changed to include Link Aggregation Control Protocol (LACP) fast switchover status. The number of valid values for the channel -group argument was changed. |
12.2(33)SRC |
This command was modified. The output of the showetherchannelport-channel and the showetherchanneldetailcommands was changed to show the status of the LACP Single Fault Direct Load Balance Swap feature, to show the last applied hash distribution algorithm, and to include LACP fast switchover status. |
12.2(33)SXI3 |
This command was modified. The output of the showetherchannelsummary, showetherchannelport-channel, and showetherchanneldetail commands was changed to show the standalone disable option. |
Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers
The channel-group argument supports six EtherChannels and eight ports in each channel.
If you do not specify a value for the channel-group argument, all channel groups are displayed.
Cisco Catalyst Switches
The number of valid values for the channel-group argument depends on the software release. For software releases prior to Cisco IOS Release 12.1(3a)E3, valid values are from 1 to 256; for Cisco IOS Release 12.1(3a)E3, 12.1(3a)E4, and 12.1(4)E1, valid values are from 1 to 64. Cisco IOS Release 12.1(5c)EX and later support a maximum of 64 values ranging from 1 to 256. Cisco IOS Release 12.2(33)SXH supports a maximum of 64 values ranging fro m 1 to 282.
If you do not specify a value for the channel-group argument, all channel groups are displayed.
In the output, the Passive port list field is displayed for Layer 3 port channels only. This field means that the physical interface, which is still not up, is configured to be in the channel group (and indirectly in the only port channel in the channel group).
The channel-groupvalues from 257 to 282 are supported on the Catalyst 6500 series Cisco Services Module (CSM) and the Catalyst 6500 series Firewall Services Module (FWSM) only.
In the output, the Passive port list field is displayed for Layer 3 port channels only. This field means that the physical interface, which is still not up, is configured to be in the channel group (and indirectly is the only port channel in the channel group).
If the interface is configured as part of the channel in ON mode, theshowetherchannelprotocol command displays Protocol: - (Mode ON).
In the output of the showetherchannelsummary command, the following conventions apply:
In the column that displays the protocol that is used for the channel, if the channel mode is ON, a hyphen (-) is displayed.
For LACP, multiple aggregators are supported. For example, if two different bundles are created, Po1 indicates the primary aggregator, and Po1A and Po1B indicates the secondary aggregators.
In the output of the showetherchannelload-balance command, the following conventions apply:
For EtherChannel load balancing of IPv6 traffic, if the traffic is bridged onto an EtherChannel (for example, it is a Layer 2 channel and traffic in the same VLAN is bridged across it), the traffic is always load balanced by the IPv6 addresses or src, dest, or src-dest, depending on the configuration. For this reason, the switch ignores the MAC/IP/ports for bridged IPv6 traffic. If you configure src-dst-mac, the src-dst-ip(v6) address is displayed. If you configure src-mac, the src-ip(v6) address is displayed.
IPv6 traffic that is routed over a Layer 2 or a Layer 3 channel is load balanced based on MAC addresses or IPv6 addresses, depending on the configuration. The MAC/IP and the src/dst/src-dst are supported, but load balancing that is based on Layer 4 ports is not supported. If you use the port keyword, the IPv6 addresses or either src, dst, or src-dst, is displayed.
The following example shows how to display the enabled protocol:
Router# show etherchannel protocol Channel-group listing: ----------------------- Group: 12 ---------- Protocol: PAgP Group: 24 ---------- Protocol: - (Mode ON) Router#
The following example shows how to display port channel information for a specific group:
Router# show etherchannel 12 port-channel Group: 12 ---------- Port-channels in the group: ---------------------- Port-channel: Po1 ------------ Age of the Port-channel = 143h:01m:12s Logical slot/port = 14/1 Number of ports = 2 GC = - HotStandBy port = null Port state = Port-channel Ag-Inuse Protocol = LACP Fast-switchover = enabled Ports in the Port-channel: Index Load Port EC state ------+------+------+------------ 0 55 Fa4/1 active 1 AA Fa4/2 active Time since last port bundled: 16h:28m:58s Fa4/1 Time since last port Un-bundled: 16h:29m:00s Fa4/4
The following example shows that direct load swapping is enabled.
Router# show etherchannel 15 port-channel Port-channels in the group: Port-channel: Po15 (Primary Aggregator) Age of the Port-channel = 0d:18h:16m:49s Logical slot/port = 14/7 Number of ports = 1 HotStandBy port = null Port state = Port-channel Ag-Inuse Protocol = LACP ! The following line of output is added with support of the LACP Single Fault Direct Load Swapping feature. ! Direct Load Swap = enabled Ports in the Port-channel: Index Load Port EC state No of bits ------+------+------+------------------+----------- 0 FF Fa4/1 Active 8 Time since last port bundled: 0d:00h:06m:12s Fa4/1
The following examples show how to display load-balancing information:
Router# show etherchannel load-balance Source XOR Destination mac address Router# show etherchannel load-balance EtherChannel Load-Balancing Configuration: dst-mac mpls label-ip EtherChannel Load-Balancing Addresses Used Per-Protocol: Non-IP: Destination MAC address IPv4: Destination MAC address IPv6: Destination MAC address (routed packets) Destination IP address (bridged packets) MPLS: Label or IP
The following example shows how to display a summary of information for a specific group:
Router# show etherchannel 1 brief Group state = L3 Ports: 2 Maxports = 8 port-channels: 1 Max port-channels = 1 Partner’s information:
The following example shows the hash distribution algorithm that was last applied:
Router# show etherchannel 10 summary Flags: D - down P - bundled in port-channel I - stand-alone s - suspended H - Hot-standby (LACP only) R - Layer3 S - Layer2 U - in use N - not in use, no aggregation f - failed to allocate aggregator <snip> Group Port-channel Protocol Ports ------+-------------+-----------+----------------------------------------------- 10 Po10(RU) LACP Gi3/7(P) Gi3/9(P) ! The following line of output is added with support of the EtherChannel Load Distribution feature. ! Last applied Hash Distribution Algorithm: Fixed Router#
The following example shows how to display detailed information for a specific group:
Router# show etherchannel 12 detail Group state = L2 Ports: 1 Maxports = 8 Port-channels: 1 Max Port-channels = 1 Protocol: PAgP Fast-switchover = enabled Ports in the group: ------------------- Port: Fa5/2 ------------ Port state = Down Not-in-Bndl Channel group = 12 Mode = Desirable-Sl Gcchange = 0 Port-channel = null GC = 0x00000000 Pseudo port-channel = Po1 2 Port index = 0 Load = 0x00 Protocol = PAgP Flags: S - Device is sending Slow LACPDUs F - Device is sending fast LACPDUs A - Device is in active mode P - Device is in passive mode Local information: LACP Port Admin Oper Port Port Port Flags State Priority Key Key Number State Fa4/1 SA bndl 32768 100 100 0xc1 0x75 Partner’s information: Partner Partner Partner Port System ID Port Number Age Flags Fa4/1 8000,00b0.c23e.d861 0x81 14s SP LACP Partner Partner Partner Port Priority Oper Key Port State 32768 128 0x81 Age of the port in the current state: 16h:27m:42s Port-channels in the group: ---------------------- Port-channel: Po12 ------------ Age of the Port-channel = 04d:02h:52m:26s Logical slot/port = 14/1 Number of ports = 0 GC = 0x00000000 HotStandBy port = null Port state = Port-channel Ag-Not-Inuse Protocol = PAgP
Note | When LACP 1:1 redundancy is configured, the showetherchanneldetail command also displays fast-switchover status information. |
The following example shows how to display a one-line summary per channel group:
Router# show etherchannel summary U-in use I-in port-channel S-suspended D-down i-stand-alone d-default Group Port-channel Ports ----- ------------ ---------------------------------------------------------- 1 Po1(U) Fa5/4(I) Fa5/5(I) 2 Po2(U) Fa5/6(I) Fa5/7(I) 255 Fa5/9(i) 256 Fa5/8(i)
The following example shows how to display EtherChannel port information for all ports and all groups:
Router# show etherchannel port Channel-group listing: ----------------------- Group: 1 ---------- Ports in the group: ------------------- Port: Fa5/4 ------------ Port state = EC-Enbld Down Not-in-Bndl Usr-Config Channel group = 1 Mode = Desirable Gcchange = 0 Port-channel = null GC = 0x00000000 Psudo-agport = Po1 Port indx = 0 Load = 0x00 Flags: S - Device is sending Slow hello. C - Device is in Consistent state. A - Device is in Auto mode. P - Device learns on physical port. Timers: H - Hello timer is running. Q - Quit timer is running. S - Switching timer is running. I - Interface timer is running. Local information: Hello Partner PAgP Learning Group Port Flags State Timers Interval Count Priority Method Ifindex Fa5/4 d U1/S1 1s 0 128 Any 0 Age of the port in the current state: 02h:40m:35s Port: Fa5/5 ------------ Port state = EC-Enbld Down Not-in-Bndl Usr-Config Channel group = 1 Mode = Desirable Gcchange = 0 Port-channel = null GC = 0x00000000 Psudo-agport = Po1 Port indx = 0 Load = 0x00 Flags: S - Device is sending Slow hello. C - Device is in Consistent state. A - Device is in Auto mode. P - Device learns on physical port. Timers: H - Hello timer is running. Q - Quit timer is running. S - Switching timer is running. I - Interface timer is running.
The following example shows how to display the information about the EtherChannel port for a specific group:
Router# show etherchannel 1 port Channel-group listing: ----------------------- Group: 1 ---------- Ports in the group: ------------------- Port: Fa5/4 ------------ Port state = EC-Enbld Down Not-in-Bndl Usr-Config Channel group = 1 Mode = Desirable Gcchange = 0 Port-channel = null GC = 0x00000000 Psudo-agport = Po1 Port index = 0 Load = 0x00 Protocol = LACP Flags: S - Device is sending Slow LACPDUs F - Device is sending fast LACPDUs A - Device is in active mode P - Device is in passive mode Local information: LACP Port Admin Oper Port Port Port Flags State Priority Key Key Number State Fa5/4 SA bndl 32768 100 100 0xc1 0x75 Partner’s information: Partner Partner Partner Port System ID Port Number Age Flags Fa5/4 8000,00b0.c23e.d861 0x81 14s SP LACP Partner Partner Partner Port Priority Oper Key Port State 32768 128 0x81 Age of the port in the current state: 04d:02h:57m:38s
The following example shows the showetherchannelsummary command output with a port in suspended state:
Router# show etherchannel 42 summary Flags: D - down P - bundled in port-channel I - stand-alone s - suspended H - Hot-standby (LACP only) R - Layer3 S - Layer2 U - in use f - failed to allocate aggregator M - not in use, minimum links not met u - unsuitable for bundling w - waiting to be aggregated Number of channel-groups in use: 8 Number of aggregators: 8 Group Port-channel Protocol Ports ------+-------------+-----------+----------------------------------------------- 2 Po42(SU) LACP Fa1/17(s) Fa1/18(P) Fa1/19(P) Fa1/20(P)
The following example shows the showetherchannelport-channel command output with the status of Standalone Disable option:
Router# show etherchannel 42 port-channel Port-channels in the group: ---------------------- Port-channel: Po42 (Primary Aggregator) ------------ Age of the Port-channel = 0d:21h:28m:22s Logical slot/port = 14/42 Number of ports = 3 HotStandBy port = null Port state = Port-channel Ag-Inuse Protocol = LACP Fast-switchover = disabled Load share deferral = disabled Standalone Disable = enabled Ports in the Port-channel: Index Load Port EC state No of bits ------+------+------------+------------------+----------- 2 49 Fa1/18 Active 3 1 92 Fa1/19 Active 3 3 24 Fa1/20 Active 2 Time since last port bundled: 0d:03h:37m:07s Fa1/18 Time since last port Un-bundled: 0d:03h:34m:27s Fa1/17 Last applied Hash Distribution Algorithm: Fixed
The following example shows the showetherchanneldetail command output with the status of Standalone Disable option:
Router# show etherchannel 42 detail Group state = L2 Ports: 4 Maxports = 16 Port-channels: 1 Max Port-channels = 16 Protocol: LACP Minimum Links: 2 Standalone Disable: enabled Ports in the group: ------------------- Port: Fa1/17 ------------ Port state = Up Cnt-bndl Suspend Not-in-Bndl Channel group = 42 Mode = Active Gcchange = - Port-channel = null GC = - Pseudo port-channel = Po2 Port index = 0 Load = 0x00 Protocol = LACP Flags: S - Device is sending Slow LACPDUs F - Device is sending fast LACPDUs. A - Device is in active mode. P - Device is in passive mode. Local information: LACP port Admin Oper Port Port Port Flags State Priority Key Key Number State Fa1/17 FP susp 1 0x2 0x2 0x112 0x82 Partner's information: Partner Partner LACP Partner Partner Partner Partner Partner Port Flags State Port Priority Admin Key Oper Key Port Number Port State Fa1/17 FP susp 1 0x0 0x2 0x312 0x36 Age of the port in the current state: 0d:03h:44m:04s Port: Fa1/18 ------------ Port state = Up Mstr In-Bndl Channel group = 42 Mode = Active Gcchange = - Port-channel = Po2 GC = - Pseudo port-channel = Po2 Port index = 2 Load = 0x49 Protocol = LACP Flags: S - Device is sending Slow LACPDUs F - Device is sending fast LACPDUs. A - Device is in active mode. P - Device is in passive mode. Local information: LACP port Admin Oper Port Port Port Flags State Priority Key Key Number State Fa1/18 SA bndl 2 0x2 0x2 0x113 0x3D Partner's information: Partner Partner LACP Partner Partner Partner Partner Partner Port Flags State Port Priority Admin Key Oper Key Port Number Port State Fa1/18 SA bndl 2 0x0 0x2 0x313 0x3D Age of the port in the current state: 0d:03h:43m:24s Port-channels in the group: Port-channel: Po42 (Primary Aggregator) Age of the Port-channel = 0d:21h:34m:45s Logical slot/port = 14/42 Number of ports = 3 HotStandBy port = null Port state = Port-channel Ag-Inuse Protocol = LACP Fast-switchover = disabled Load share deferral = disabled Standalone Disable = enabled Ports in the Port-channel: Index Load Port EC state No of bits ------+------+------------+------------------+----------- 2 49 Fa1/18 Active 3 1 92 Fa1/19 Active 3 3 24 Fa1/20 Active 2 Time since last port bundled: 0d:03h:43m:30s Fa1/18 Time since last port Un-bundled: 0d:03h:40m:50s Fa1/17 Last applied Hash Distribution Algorithm: Fixed
Command |
Description |
---|---|
channel-group |
Assigns and configures an EtherChannel interface to an EtherChannel group. |
channel-protocol |
Sets the protocol that is used on an interface to manage channeling. |
interface port-channel |
Accesses or creates the IDB port channel. |
To display statistics for all interfaces configured on the router or access server, use the show interfaces command in privileged EXEC mode.
show interfaces [ type number ] [first] [last] [accounting]
show interfaces [ type slot/port ] [ accounting | counters protocol status | crb | dampening | description | dot1ad | etherchannel [ module number ] | fair-queue | irb | mac-accounting | mpls-exp | precedence | random-detect | rate-limit | stats | summary | switching | utilization { type number } ]
show interfaces [ type slot/port-adapter/port ]
show interfaces [ type number | null interface-number | vlan vlan-id ]
show interfaces serial [ slot/subslot/port/t1-num : channel-group ]
show interfaces type [ slot/subslot/port [ /sub-int ] ]
User EXEC (>)
Privileged EXEC (#)
Release |
Modification |
---|---|
10.0 |
This command was introduced. |
12.0(3)T |
This command was modified to include support for flow-based WRED . |
12.0(4)T |
This command was modified to include enhanced display information for dialer bound interfaces. |
12.0(7)T |
This command was modified to include dialer as an interface type and to reflect the default behavior. |
12.2(14)S |
This command was integrated into Cisco IOS Release 12.2(14)S. |
12.2(20)S2 |
This command was integrated into Cisco IOS Release 12.2(20)S2 and introduced a new address format and output for SPA interfaces on the Cisco 7304 router. The subslot argument was introduced. |
12.2(25)S3 |
This command was integrated into Cisco IOS Release 12.2(25)S3. |
12.2(14)SX |
This command was modified. Support for this command was added for the Supervisor Engine 720. |
12.2(17d)SXB |
This command was modified. Support for this command on the Supervisor Engine 2 was extended to Cisco IOS Release 12.2SX. The uplink dual-mode port information was updated. |
12.2(18)SXE |
This command was integrated into Cisco IOS Release 12.2(18)SXE to support SPAs on the Cisco 7600 series routers and Catalyst 6500 series switches. |
2.2(33)SXJ01 |
This command was integrated into Cisco IOS Release 12.2(33)SXJ01. |
12.0(31)S |
This command was integrated into Cisco IOS Release 12.0(31)S to support SPAs on the Cisco 12000 series routers, and the tengigabitethernet interface type was added. 10-Gigabit Ethernet interfaces were introduced with the release of the 1-Port 10-Gigabit Ethernet SPA. |
12.2(18)SXF |
This command was integrated into Cisco IOS Release 12.2(18)SXF. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
12.2(33)SRB1 |
This command was updated to display operational status for Gigabit Ethernet interfaces that are configured as primary and backup interfaces (Cisco 7600 series routers). |
12.2(31)SB |
This command was integrated in Cisco IOS Release 12.2(31)SB. |
12.2(33)SB |
This command was modified. The default value of the command was modified on the Cisco 10000 series router for the PRE3 and PRE4. |
Cisco IOS XE Release 2.5 |
This command was implemented on Cisco ASR 1000 Series Aggregation Services Routers. |
12.2(50)SY |
This command was integrated in Cisco IOS Release 12.2(50)SY and the dot1ad keyword was added. |
15.1(01)SY |
This command was integrated in Cisco IOS Release 15.1(50)SY. |
Display Interpretation
The show interfaces command displays statistics for the network interfaces. The resulting output varies, depending on the network for which an interface has been configured. The resulting display on the Cisco 7200 series routers shows the interface processors in slot order. If you add interface processors after booting the system, they will appear at the end of the list, in the order in which they were inserted.
Information About Specific Interfaces
The number argument designates the module and port number. If you use the show interfaces command on the Cisco 7200 series routers without the slot/port arguments, information for all interface types will be shown. For example, if you type show interfaces you will receive information for all Ethernet, serial, Token Ring, and FDDI interfaces. Only by adding the type slot/port argument you can specify a particular interface.
Cisco 7600 Series Routers
Valid values for the number argument depend on the specified interface type and the chassis and module that are used. For example, if you specify a Gigabit Ethernet interface and have a 48-port 10/100BASE-T Ethernet module that is installed in a 13-slot chassis, valid values for the module number are from 1 to 13 and valid values for the port number are from 1 to 48.
The port channels from 257 to 282 are internally allocated and are supported on the Content Switching Module (CSM) and the Firewall Services Module (FWSM) only.
Statistics are collected on a per-VLAN basis for Layer 2-switched packets and Layer 3-switched packets. Statistics are available for both unicast and multicast traffic. The Layer 3-switched packet counts are available for both ingress and egress directions. The per-VLAN statistics are updated every 5 seconds.
In some cases, you might see a difference in the duplex mode that is displayed between the show interfaces command and the show running-configcommands. In this case, the duplex mode that is displayed in the show interfaces command is the actual duplex mode that the interface is running. The show interfaces command shows the operating mode for an interface, and the show running-config command shows the configured mode for an interface.
If you do not enter any keywords, all counters for all modules are displayed.
Command Variations
You will use the show interfaces command frequently while configuring and monitoring devices. The various forms of the show interfaces commands are described in detail in the sections that follow.
Dialer Interfaces Configured for Binding
If you use the show interfaces command on dialer interfaces configured for binding, the display will report statistics on each physical interface bound to the dialer interface; see the following examples for more information.
Removed Interfaces
If you enter a show interfaces command for an interface type that has been removed from the router or access server, interface statistics will be displayed accompanied by the following text: “Hardware has been removed.”
Weighted Fair Queueing Information
If you use the show interfaces command on a router or access server for which interfaces are configured to use weighted fair queueing through the fair-queue interface command, additional information is displayed. This information consists of the current and high-water mark number of flows.
Cisco 10000 Series Router
In Cisco IOS Release 12.2(33)SB, when a multilink PPP (MLP) interface is down/down, its default bandwidth rate is the sum of the serial interface bandwidths associated with the MLP interface.
In Cisco IOS Release 12.2(31)SB, the default bandwidth rate is 64 Kbps.
The following is sample output from the show interfaces command. Because your display will depend on the type and number of interface cards in your router or access server, only a portion of the display is shown.
Note | If an asterisk (*) appears after the throttles counter value, it means that the interface was throttled at the time the command was run. |
Router# show interfaces Ethernet 0 is up, line protocol is up Hardware is MCI Ethernet, address is 0000.0c00.750c (bia 0000.0c00.750c) Internet address is 10.108.28.8, subnet mask is 255.255.255.0 MTU 1500 bytes, BW 10000 Kbit, DLY 100000 usec, rely 255/255, load 1/255 Encapsulation ARPA, loopback not set, keepalive set (10 sec) ARP type: ARPA, ARP Timeout 4:00:00 Last input 0:00:00, output 0:00:00, output hang never Last clearing of "show interface" counters 0:00:00 Output queue 0/40, 0 drops; input queue 0/75, 0 drops Five minute input rate 0 bits/sec, 0 packets/sec Five minute output rate 2000 bits/sec, 4 packets/sec 1127576 packets input, 447251251 bytes, 0 no buffer Received 354125 broadcasts, 0 runts, 0 giants, 57186* throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 5332142 packets output, 496316039 bytes, 0 underruns 0 output errors, 432 collisions, 0 interface resets, 0 restarts . . .
The following example shows partial sample output when custom output queueing is enabled:
Router# show interfaces Last clearing of “show interface” counters 0:00:06 Input queue: 0/75/0 (size/max/drops); Total output drops: 21 Output queues: (queue #: size/max/drops) 0: 14/20/14 1: 0/20/6 2: 0/20/0 3: 0/20/0 4: 0/20/0 5: 0/20/0 6: 0/20/0 7: 0/20/0 8: 0/20/0 9: 0/20/0 10: 0/20/0 . . .
When custom queueing is enabled, the drops accounted for in the output queues result from bandwidth limitation for the associated traffic and lead to queue length overflow. Total output drops include drops on all custom queues and the system queue. Fields are described with the weighted fair queueing output in the table below.
For each interface on the router or access server configured to use weighted fair queueing, the show interfaces command displays the information beginning with Inputqueue: in the following display:
Router# show interfaces Ethernet 0 is up, line protocol is up Hardware is MCI Ethernet, address is 0000.0c00.750c (bia 0000.0c00.750c) Internet address is 10.108.28.8, subnet mask is 255.255.255.0 MTU 1500 bytes, BW 10000 Kbit, DLY 100000 usec, rely 255/255, load 1/255 Encapsulation ARPA, loopback not set, keepalive set (10 sec) ARP type: ARPA, ARP Timeout 4:00:00 Last input 0:00:00, output 0:00:00, output hang never Last clearing of “show interface” counters 0:00:00 Output queue 0/40, 0 drops; input queue 0/75, 0 drops Five minute input rate 0 bits/sec, 0 packets/sec Five minute output rate 2000 bits/sec, 4 packets/sec 1127576 packets input, 447251251 bytes, 0 no buffer Received 354125 broadcasts, 0 runts, 0 giants, 57186* throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 5332142 packets output, 496316039 bytes, 0 underruns 0 output errors, 432 collisions, 0 interface resets, 0 restarts Input queue: 0/75/0 (size/max/drops); Total output drops: 0 Output queue: 7/64/0 (size/threshold/drops) Conversations 2/9 (active/max active)
The table below describes the input queue and output queue fields shown in the preceding two displays.
Field |
Description |
---|---|
Input Queue |
|
size |
Current size of the input queue. |
max |
Maximum size of the queue. |
drops |
Number of messages discarded in this interval. |
Total output drops |
Total number of messages discarded in this session. |
Output Queue |
|
size |
Current size of the output queue. |
threshold |
Congestive-discard threshold. Number of messages in the queue after which new messages for high-bandwidth conversations are dropped. |
drops |
Number of dropped messages. |
Conversations: active |
Number of currently active conversations. |
Conversations: max active |
Maximum number of concurrent conversations allowed. |
To display the number of packets of each protocol type that have been sent through all configured interfaces, use the show interfaces accounting command. When you use the accounting option, only the accounting statistics are displayed.
Note | Except for protocols that are encapsulated inside other protocols, such as IP over X.25, the accounting option also shows the total bytes sent and received, including the MAC header. For example, it totals the size of the Ethernet packet or the size of a packet that includes High-Level Data Link Control (HDLC) encapsulation. |
Per-packet accounting information is kept for the following protocols:
AppleTalk
Address Resolution Protocol (ARP) (for IP, Frame Relay, Switched Multimegabit Data Service (SMDS))
Connectionless Network Service (CLNS)
Digital Equipment Corporation (DEC) Maintenance Operations Protocol (MOP)
The routers use MOP packets to advertise their existence to Digital Equipment Corporation machines that use the MOP. A router periodically broadcasts MOP packets to identify itself as a MOP host. This results in MOP packets being counted, even when DECnet is not being actively used.
The following is sample output from the show interfaces command when distributed WRED (DWRED) is enabled on an interface. Notice that the packet drop strategy is listed as “VIP-based weighted RED.”
Router# show interfaces hssi 0/0/0 Hssi0/0/0 is up, line protocol is up Hardware is cyBus HSSI Description: 45Mbps to R1 Internet address is 10.200.14.250/30 MTU 4470 bytes, BW 45045 Kbit, DLY 200 usec, rely 255/255, load 1/255 Encapsulation HDLC, loopback not set, keepalive set (10 sec) Last input 00:00:02, output 00:00:03, output hang never Last clearing of "show interface" counters never Queueing strategy: fifo Packet Drop strategy: VIP-based weighted RED Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 1976 packets input, 131263 bytes, 0 no buffer Received 1577 broadcasts, 0 runts, 0 giants 0 parity 4 input errors, 4 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 1939 packets output, 130910 bytes, 0 underruns 0 output errors, 0 applique, 3 interface resets 0 output buffers copied, 0 interrupts, 0 failures
The following is sample output from the show interfaces command for serial interface 2 when Airline Control (ALC) Protocol is enabled:
Router# show interfaces serial 2 Serial2 is up, line protocol is up Hardware is CD2430 MTU 1500 bytes, BW 115 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation ALC, loopback not set Full-duplex enabled. ascus in UP state: 42, 46 ascus in DOWN state: ascus DISABLED: Last input never, output never, output hang never Last clearing of “show interface” counters never Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 0 packets input, 0 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 0 packets output, 0 bytes, 0 underruns 0 output errors, 0 collisions, 3 interface resets 0 output buffer failures, 0 output buffers swapped out DCD=down DSR=down DTR=down RTS=down CTS=down
The following is sample output from the show interfaces command for an SDLC primary interface supporting the SDLC function:
Router# show interfaces Serial 0 is up, line protocol is up Hardware is MCI Serial MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation SDLC-PRIMARY, loopback not set Timers (msec): poll pause 100 fair poll 500. Poll limit 1 [T1 3000, N1 12016, N2 20, K 7] timer: 56608 Last polled device: none SDLLC [ma: 0000.0C01.14--, ring: 7 bridge: 1, target ring: 10 largest token ring frame 2052] SDLC addr C1 state is CONNECT VS 6, VR 3, RCNT 0, Remote VR 6, Current retransmit count 0 Hold queue: 0/12 IFRAMEs 77/22 RNRs 0/0 SNRMs 1/0 DISCs 0/0 Poll: clear, Poll count: 0, chain: p: C1 n: C1 SDLLC [largest SDLC frame: 265, XID: disabled] Last input 00:00:02, output 00:00:01, output hang never Output queue 0/40, 0 drops; input queue 0/75, 0 drops Five minute input rate 517 bits/sec, 30 packets/sec Five minute output rate 672 bits/sec, 20 packets/sec 357 packets input, 28382 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 926 packets output, 77274 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets, 0 restarts 2 carrier transitions
The table below shows the fields relevant to all SDLC connections.
Field |
Description |
---|---|
Timers (msec) |
List of timers in milliseconds. |
poll pause, fair poll, Poll limit |
Current values of these timers. |
T1, N1, N2, K |
Current values for these variables. |
The table below shows other data given for each SDLC secondary interface configured to be attached to this interface.
Field |
Description |
---|---|
addr |
Address of this secondary interface. |
State |
Current state of this connection. The possible values follow:
|
VS |
Sequence number of the next information frame this station sends. |
VR |
Sequence number of the next information frame from this secondary that this station expects to receive. |
RCNT |
Number of correctly sequenced I-frames received when the Cisco IOS software was in a state in which it is acceptable to receive I-frames. |
Remote VR |
Last frame transmitted by this station that has been acknowledged by the other station. |
Current retransmit count |
Number of times the current I-frame or sequence of I-frames has been retransmitted. |
Hold queue |
Number of frames in hold queue/Maximum size of hold queue. |
IFRAMEs, RNRs, SNRMs, DISCs |
Sent and received count for these frames. |
Poll |
“Set” if this router has a poll outstanding to the secondary; “clear” if it does not. |
Poll count |
Number of polls, in a row, given to this secondary at this time. |
chain |
Shows the previous (p) and next (n) secondary address on this interface in the round-robin loop of polled devices. |
The following is sample output from the show interfaces accounting command:
Router# show interfaces accounting Interface TokenRing0 is disabled Ethernet0 Protocol Pkts In Chars In Pkts Out Chars Out IP 873171 735923409 34624 9644258 Novell 163849 12361626 57143 4272468 DEC MOP 0 0 1 77 ARP 69618 4177080 1529 91740 Interface Serial0 is disabled Ethernet1 Protocol Pkts In Chars In Pkts Out Chars Out IP 0 0 37 11845 Novell 0 0 4591 275460 DEC MOP 0 0 1 77 ARP 0 0 7 420 Interface Serial1 is disabled Interface Ethernet2 is disabled Interface Serial2 is disabled Interface Ethernet3 is disabled Interface Serial3 is disabled Interface Ethernet4 is disabled Interface Ethernet5 is disabled Interface Ethernet6 is disabled Interface Ethernet7 is disabled Interface Ethernet8 is disabled Interface Ethernet9 is disabled Fddi0 Protocol Pkts In Chars In Pkts Out Chars Out Novell 0 0 183 11163 ARP 1 49 0 0
When the output indicates that an interface is “ disabled,” the router has received excessive errors (over 5000 in a keepalive period).
The following is sample output from the show interfaces command issued for the serial interface 1 for which flow-based WRED is enabled. The output shows that there are 8 active flow-based WRED flows, that the maximum number of flows active at any time is 9, and that the maximum number of possible flows configured for the interface is 16:
Router# show interfaces serial 1 Serial1 is up, line protocol is up Hardware is HD64570 Internet address is 10.1.2.1/24 MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, Reliability 255/255, txload 237/255, rxload 1/255 Encapsulation HDLC, loopback not set Keepalive not set Last input 00:00:22, output 00:00:00, output hang never Last clearing of "show interface" counters 00:17:58 Input queue: 0/75/0 (size/max/drops); Total output drops: 2479 Queueing strategy: random early detection(RED) flows (active/max active/max): 8/9/16 mean queue depth: 27 drops: class random tail min-th max-th mark-prob 0 946 0 20 40 1/10 1 488 0 22 40 1/10 2 429 0 24 40 1/10 3 341 0 26 40 1/10 4 235 0 28 40 1/10 5 40 0 31 40 1/10 6 0 0 33 40 1/10 7 0 0 35 40 1/10 rsvp 0 0 37 40 1/10 30 second input rate 1000 bits/sec, 2 packets/sec 30 second output rate 119000 bits/sec, 126 packets/sec 1346 packets input, 83808 bytes, 0 no buffer Received 12 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 84543 packets output, 9977642 bytes, 0 underruns 0 output errors, 0 collisions, 6 interface resets 0 output buffer failures, 0 output buffers swapped out 0 carrier transitions DCD=up DSR=up DTR=up RTS=up CTS=up
The following is sample output from the show interfaces command when distributed weighted fair queueing (DWFQ) is enabled on an interface. Notice that the queueing strategy is listed as “VIP-based fair queueing.”
Router# show interfaces fastethernet 1/1/0 Fast Ethernet 1/1/0 is up, line protocol is up Hardware is cyBus Fast Ethernet Interface, address is 0007.f618.4448 (bia 00e0) Description: pkt input i/f for WRL tests (to pagent) Internet address is 10.0.2.70/24 MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, rely 255/255, load 1/255 Encapsulation ARPA, loopback not set, keepalive not set, fdx, 100BaseTX/FX ARP type: ARPA, ARP Timeout 04:00:00 Last input never, output 01:11:01, output hang never Last clearing of "show interface" counters 01:12:31 Queueing strategy: VIP-based fair queueing Output queue 0/40, 0 drops; input queue 0/75, 0 drops 30 second input rate 0 bits/sec, 0 packets/sec 30 second output rate 0 bits/sec, 0 packets/sec 0 packets input, 0 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 0 watchdog, 0 multicast 0 input packets with dribble condition detected 1 packets output, 60 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffers copied, 0 interrupts, 0 failures
When the show interfaces command is issued on an unbound dialer interface, the output looks as follows:
Router# show interfaces dialer 0 Dialer0 is up (spoofing), line protocol is up (spoofing) Hardware is Unknown Internet address is 10.1.1.2/8 MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec, rely 255/255, load 3/255 Encapsulation PPP, loopback not set DTR is pulsed for 1 seconds on reset Last input 00:00:34, output never, output hang never Last clearing of “show interface” counters 00:05:09 Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 1000 bits/sec, 0 packets/sec 18 packets input, 2579 bytes 14 packets output, 5328 bytes
But when the show interfaces command is issued on a bound dialer interface, you will get an additional report that indicates the binding relationship. The output is shown here:
Router# show interfaces dialer 0 Dialer0 is up, line protocol is up Hardware is Unknown Internet address is 10.1.1.2/8 MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation PPP, loopback not set DTR is pulsed for 1 seconds on reset Interface is bound to BRI0:1 Last input 00:00:38, output never, output hang never Last clearing of “show interface” counters 00:05:36 Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 38 packets input, 4659 bytes 34 packets output, 9952 bytes Bound to: BRI0:1 is up, line protocol is up Hardware is BRI MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation PPP, loopback not set, keepalive not set Interface is bound to Dialer0 (Encapsulation PPP) LCP Open, multilink Open Last input 00:00:39, output 00:00:11, output hang never Last clearing of “show interface” counters never Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 78 packets input, 9317 bytes, 0 no buffer Received 65 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 93 packets output, 9864 bytes, 0 underruns 0 output errors, 0 collisions, 7 interface resets 0 output buffer failures, 0 output buffers swapped out 4 carrier transitions
At the end of the Dialer0 output, the show interfaces command is executed on each physical interface bound to it.
The following is sample output from the show interfaces dialer stats command:
Router# show interfaces dialer 0 stats Dialer0 Switching path Pkts In Chars In Pkts Out Chars Out Processor 0 0 6 1694 Route cache 2522229 610372530 720458 174343542 Total 2522229 610372530 720464 174345236
In this example, the physical interface is the B1 channel of the BRI0 link. This example also illustrates that the output under the B channel keeps all hardware counts that are not displayed under any logical or virtual access interface. The line in the report that states “Interface is bound to Dialer0 (Encapsulation LAPB)” indicates that the B interface is bound to Dialer0 and the encapsulation running over this connection is Link Access Procedure, Balanced (LAPB), not PPP, which is the encapsulation configured on the D interface and inherited by the B channel.
Router# show interfaces bri0:1 BRI0:1 is up, line protocol is up Hardware is BRI MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation PPP, loopback not set, keepalive not set Interface is bound to Dialer0 (Encapsulation LAPB) LCP Open, multilink Open Last input 00:00:31, output 00:00:03, output hang never Last clearing of “show interface” counters never Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 1 packets/sec 5 minute output rate 0 bits/sec, 1 packets/sec 110 packets input, 13994 bytes, 0 no buffer Received 91 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 135 packets output, 14175 bytes, 0 underruns 0 output errors, 0 collisions, 12 interface resets 0 output buffer failures, 0 output buffers swapped out 8 carrier transitions
Any protocol configuration and states should be displayed from the Dialer0 interface.
The following is sample output from the show interfaces fastethernet command for the second interface (port 1) in a 4-Port 10/100 Fast Ethernet SPA located in the bottom subslot (1) of the Modular Service Cards (MSC) that is installed in slot 2 on a Cisco 7304 router:
Router# show interfaces fastethernet 2/1/1 FastEthernet2/1/1 is up, line protocol is up Hardware is SPA-4FE-7304, address is 00b0.64ff.5d80 (bia 00b0.64ff.5d80) Internet address is 192.168.50.1/24 MTU 9216 bytes, BW 100000 Kbit, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Full-duplex, 100Mb/s, 100BaseTX/FX ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:00:22, output 00:00:02, output hang never Last clearing of "show interface" counters never Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 5 packets input, 320 bytes Received 1 broadcasts (0 IP multicast) 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog 0 input packets with dribble condition detected 8 packets output, 529 bytes, 0 underruns 0 output errors, 0 collisions, 2 interface resets 0 babbles, 0 late collision, 0 deferred 2 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out
Router# show interfaces e4/0 Ethernet4/0 is up, line protocol is up Hardware is AmdP2, address is 000b.bf30.f470 (bia 000b.bf30.f470) Internet address is 10.1.1.9/24 MTU 1500 bytes, BW 10000 Kbit, RxBW 5000 Kbit, DLY 1000 usec, reliability 255/255, txload 1/255, rxload 254/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:00:00, output 00:00:01, output hang never Last clearing of "show interface" counters 00:03:36 Input queue: 34/75/0/819 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 30 second input rate 7138000 bits/sec, 14870 packets/sec 30 second output rate 0 bits/sec, 0 packets/sec 3109298 packets input, 186557880 bytes, 0 no buffer Received 217 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 input packets with dribble condition detected 22 packets output, 1320 bytes, 0 underruns 11 output errors, 26 collisions, 0 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out
The table below describes the significant fields shown in the display.
Field |
Description |
||
---|---|---|---|
Fast Ethernet...is up ...is administratively down |
Indicates whether the interface hardware is currently active and if it has been taken down by an administrator. |
||
line protocol is |
Indicates whether the software processes that handle the line protocol consider the line usable or if it has been taken down by an administrator. |
||
Hardware |
Hardware type (for example, SPA-4FE-7304) and MAC address. |
||
Description |
Alphanumeric string identifying the interface. This appears only if the description interface configuration command has been configured on the interface. |
||
Internet address |
Internet address followed by subnet mask. |
||
MTU |
Maximum transmission unit of the interface. The default is 1500 bytes for the 4-Port 10/100 Fast Ethernet SPA. |
||
BW |
Bandwidth of the interface in kilobits per second. |
||
RxBW |
Receiver bandwidth of the interface, in kilobits per second. This value is displayed only when an interface has asymmetric receiver and transmitter rates. |
||
DLY |
Delay of the interface in microseconds. |
||
reliability |
Reliability of the interface as a fraction of 255 (255/255 is 100 percent reliability), calculated as an exponential average over 5 minutes. |
||
txload, rxload |
Load on the interface (in the transmit “tx” and receive “rx” directions) as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes. |
||
Encapsulation |
Encapsulation method assigned to the interface. |
||
loopback |
Indicates whether loopback is set. |
||
Keepalive |
Indicates whether keepalives are set, and the time interval. |
||
Half-duplex, Full-duplex |
Indicates the duplex mode for the interface. |
||
100Mb/s, 10Mb/s |
Speed of the interface in megabits per second. |
||
100BaseTX/FX |
Media protocol standard. |
||
ARP type: |
Type of ARP assigned and the timeout period. |
||
Last input |
Number of hours, minutes, and seconds since the last packet was successfully received by an interface and processed locally on the router. Useful for knowing when a dead interface failed. This field is not updated by fast-switched traffic. |
||
output |
Number of hours, minutes, and seconds since the last packet was successfully transmitted by the interface. Useful for knowing when a dead interface failed. |
||
output hang |
Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the “last” fields exceeds 24 hours, the number of days and hours is displayed. If that field overflows, asterisks are printed.
|
||
Last clearing |
Time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared. A series of asterisks (***) indicates the elapsed time is too large to be displayed. 0:00:00 indicates the counters were cleared more than 231 ms (and less than 232 ms) ago. |
||
Input queue (size/max/drops/flushes) |
Packet statistics on the input queue reported as:
|
||
Total output drops |
Total number of packets dropped because of a full output queue. |
||
Queueing strategy |
Type of Layer 3 queueing active on this interface. The default is first-in, first-out (FIFO). |
||
Output queue (size/max) |
Number of packets in the output queue (size), and the maximum size of the queue (max). |
||
5 minute input rate, 5 minute output rate |
Average number of bits and packets transmitted per second in the last 5 minutes. If the interface is not in promiscuous mode, it senses network traffic it sends and receives (rather than all network traffic). The 5-minute input and output rates should be used only as an approximation of traffic per second during a given 5-minute period. These rates are exponentially weighted averages with a time constant of 5 minutes. A period of four time constants must pass before the average will be within two percent of the instantaneous rate of a uniform stream of traffic over that period. |
||
packets input |
Total number of error-free packets received by the system. |
||
bytes |
Total number of bytes, including data and MAC encapsulation, in the error-free packets received by the system. |
||
Received...broadcasts |
Total number of broadcast or multicast packets received by the interface. |
||
runts |
Number of packets that are discarded because they are smaller than the minimum packet size of the medium. For instance, any Ethernet packet that is smaller than 64 bytes is considered a runt. |
||
giants |
Number of packets that are discarded because they exceed the maximum packet size of the medium. For example, any Ethernet packet that is larger than 1536 bytes is considered a giant.
|
||
throttles |
Number of times the receiver on the port was disabled, possibly because of buffer or processor overload. |
||
input errors |
Includes runts, giants, no buffer, cyclic redundancy check (CRC), frame, overrun, and ignored counts. Other input-related errors can also cause the input errors count to be increased, and some datagrams may have more than one error; therefore, this sum may not balance with the sum of enumerated input error counts. |
||
CRC |
Cyclic redundancy check generated by the originating LAN station or far-end device does not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRCs is usually the result of collisions or a station transmitting bad data. |
||
frame |
Number of packets received incorrectly having a CRC error and a noninteger number of octets. On a LAN, this is usually the result of collisions or a malfunctioning Ethernet device. |
||
overrun |
Number of times the receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver’s ability to handle the data. |
||
ignored |
Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers. Broadcast storms and bursts of noise can cause the ignored count to be increased. |
||
watchdog |
Number of times the watchdog receive timer expired. Expiration happens when receiving a packet with a length greater than 2048 bytes. |
||
input packets with dribble condition detected |
Dribble bit error indicates that a frame is slightly too long. This frame error counter is incremented for informational purposes only; the router accepts the frame. |
||
packets output |
Total number of messages transmitted by the system. |
||
bytes |
Total number of bytes, including data and MAC encapsulation, transmitted by the system. |
||
underruns |
Number of times that the transmitter has been running faster than the router can handle. |
||
output errors |
Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this may not balance with the sum of the enumerated output errors, because some datagrams may have more than one error and others may have errors that do not fall into any of the specifically tabulated categories. |
||
collisions |
Number of messages retransmitted because of an Ethernet collision. This is usually the result of an overextended LAN (Ethernet or transceiver cable too long, more than two repeaters between stations, or too many cascaded multiport transceivers). A packet that collides is counted only once in output packets. |
||
interface resets |
Number of times an interface has been completely reset. This can happen if packets queued for transmission were not sent within several seconds. Interface resets can occur when an interface is looped back or shut down. |
||
babbles |
Transmit jabber timer expired. |
||
late collision |
Number of late collisions. Late collision happens when a collision occurs after transmitting the preamble. |
||
deferred |
Number of times that the interface had to defer while ready to transmit a frame because the carrier was asserted. |
||
lost carrier |
Number of times the carrier was lost during transmission. |
||
no carrier |
Number of times the carrier was not present during the transmission.
|
||
output buffer failures, output buffers swapped out |
These counters are not used by the 4-Port 10/100 Fast Ethernet SPA on the Cisco 7304 router. |
The following is sample output from the show interfaces gigabitethernet command for the first interface (port 0) in a 2-Port 10/100/1000 Gigabit Ethernet SPA located in the top subslot (0) of the MSC that is installed in slot 4 on a Cisco 7304 router:
Router# show interfaces gigabitethernet 4/0/0 GigabitEthernet4/0/0 is up, line protocol is down Hardware is SPA-2GE-7304, address is 00b0.64ff.5a80 (bia 00b0.64ff.5a80) MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Half-duplex, 1000Mb/s, link type is auto, media type is RJ45 output flow-control is unsupported, input flow-control is unsupported ARP type: ARPA, ARP Timeout 04:00:00 Last input never, output 00:00:09, output hang never Last clearing of "show interface" counters never Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 0 packets input, 0 bytes, 0 no buffer Received 0 broadcasts (0 IP multicast) 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 0 multicast, 0 pause input 109 packets output, 6540 bytes, 0 underruns 0 output errors, 0 collisions, 2 interface resets 0 babbles, 0 late collision, 0 deferred 1 lost carrier, 0 no carrier, 0 PAUSE output 0 output buffer failures, 0 output buffers swapped out
The following examples show the additional lines included in the display when the command is issued on two Gigabit Ethernet interfaces that are configured as a primary interface (gi3/0/0) and as a backup interface (gi3/0/11) for the primary:
Router# show interfaces gigabitEthernet 3/0/0 GigabitEthernet3/0/0 is up, line protocol is up (connected) Hardware is GigEther SPA, address is 0005.dc57.8800 (bia 0005.dc57.8800) Backup interface GigabitEthernet3/0/11, failure delay 0 sec, secondary disable delay 0 sec, . . . Router# show interfaces gigabitEthernet 3/0/11 GigabitEthernet3/0/11 is standby mode, line protocol is down (disabled) . . .
The table below describes the fields shown in the display for Gigabit Ethernet SPA interfaces.
Field |
Description |
||
---|---|---|---|
GigabitEthernet...is up ...is administratively down |
Indicates whether the interface hardware is currently active and if it has been taken down by an administrator. |
||
line protocol is |
Indicates whether the software processes that handle the line protocol consider the line usable or if it has been taken down by an administrator. |
||
Hardware |
Hardware type (for example, SPA-2GE-7304) and MAC address. |
||
Backup interface |
Identifies the backup interface that exists for this, the primary interface. |
||
Failure and secondary delay |
The period of time (in seconds) to delay bringing up the backup interface when the primary goes down, and bringing down the backup after the primary becomes active again. On the Cisco 7600 router, the delay must be 0 (the default) to ensure that there is no delay between when the primary goes down and the backup comes up, and vice versa. |
||
Standby mode |
Indicates that this is a backup interface and that it is currently operating in standby mode. |
||
Description |
Alphanumeric string identifying the interface. This appears only if the description interface configuration command has been configured on the interface. |
||
Internet address |
Internet address followed by subnet mask. |
||
MTU |
Maximum transmission unit of the interface. The default is 1500 bytes for the 2-Port 10/100/1000 Gigabit Ethernet SPA. |
||
BW |
Bandwidth of the interface in kilobits per second. |
||
DLY |
Delay of the interface in microseconds. |
||
reliability |
Reliability of the interface as a fraction of 255 (255/255 is 100 percent reliability), calculated as an exponential average over 5 minutes. |
||
txload, rxload |
Load on the interface (in the transmit “tx” and receive “rx” directions) as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes. |
||
Encapsulation |
Encapsulation method assigned to the interface. |
||
loopback |
Indicates whether loopback is set. |
||
Keepalive |
Indicates whether keepalives are set, and the time interval. |
||
Half-duplex, Full-duplex |
Indicates the duplex mode for the interface. |
||
1000Mb/s, 100Mb/s, 10Mb/s |
Speed of the interface in megabits per second. |
||
link type |
Specifies whether autonegotiation is being used on the link. |
||
media type |
Interface port media type: RJ45, SX, LX, or ZX. |
||
100BaseTX/FX |
Media protocol standard. |
||
ARP type: |
Type of ARP assigned and the timeout period. |
||
Last input |
Number of hours, minutes, and seconds since the last packet was successfully received by an interface and processed locally on the router. Useful for knowing when a dead interface failed. This field is not updated by fast-switched traffic. |
||
output |
Number of hours, minutes, and seconds since the last packet was successfully transmitted by the interface. Useful for knowing when a dead interface failed. |
||
output hang |
Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the “last” fields exceeds 24 hours, the number of days and hours is displayed. If that field overflows, asterisks are printed.
|
||
Last clearing |
Time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared. A series of asterisks (***) indicates the elapsed time is too large to be displayed. 0:00:00 indicates the counters were cleared more than 231 ms (and less than 232 ms) ago. |
||
Input queue (size/max/drops/flushes) |
Packet statistics on the input queue reported as:
|
||
Total output drops |
Total number of packets dropped because of a full output queue. |
||
Queueing strategy |
Type of Layer 3 queueing active on this interface. The default is FIFO. |
||
Output queue (size/max) |
Number of packets in the output queue (size), and the maximum size of the queue (max). |
||
5 minute input rate, 5 minute output rate |
Average number of bits and packets transmitted per second in the last 5 minutes. If the interface is not in promiscuous mode, it senses network traffic it sends and receives (rather than all network traffic). The 5-minute input and output rates should be used only as an approximation of traffic per second during a given 5-minute period. These rates are exponentially weighted averages with a time constant of 5 minutes. A period of four time constants must pass before the average will be within two percent of the instantaneous rate of a uniform stream of traffic over that period. |
||
packets input |
Total number of error-free packets received by the system. |
||
bytes |
Total number of bytes, including data and MAC encapsulation, in the error-free packets received by the system. |
||
Received...broadcasts |
Total number of broadcast or multicast packets received by the interface. |
||
runts |
Number of packets that are discarded because they are smaller than the minimum packet size of the medium. For instance, any Ethernet packet that is smaller than 64 bytes is considered a runt. |
||
giants |
Number of packets that are discarded because they exceed the maximum packet size of the medium. For example, any Ethernet packet that is larger than 1536 bytes is considered a giant.
|
||
throttles |
Number of times the receiver on the port was disabled, possibly because of buffer or processor overload. |
||
input errors |
Includes runts, giants, no buffer, CRC, frame, overrun, and ignored counts. Other input-related errors can also cause the input errors count to be increased, and some datagrams may have more than one error; therefore, this sum may not balance with the sum of enumerated input error counts. |
||
CRC |
Cyclic redundancy check generated by the originating LAN station or far-end device does not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRCs is usually the result of collisions or a station transmitting bad data. |
||
frame |
Number of packets received incorrectly having a CRC error and a noninteger number of octets. On a LAN, this is usually the result of collisions or a malfunctioning Ethernet device. |
||
overrun |
Number of times the receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver’s ability to handle the data. |
||
ignored |
Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers. Broadcast storms and bursts of noise can cause the ignored count to be increased. |
||
watchdog |
Number of times the watchdog receive timer expired. Expiration happens when receiving a packet with a length greater than 2048 bytes. |
||
input packets with dribble condition detected |
Dribble bit error indicates that a frame is slightly too long. This frame error counter is incremented for informational purposes only; the router accepts the frame. |
||
packets output |
Total number of messages transmitted by the system. |
||
bytes |
Total number of bytes, including data and MAC encapsulation, transmitted by the system. |
||
underruns |
Number of times that the transmitter has been running faster than the router can handle. |
||
output errors |
Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this may not balance with the sum of the enumerated output errors, because some datagrams may have more than one error and others may have errors that do not fall into any of the specifically tabulated categories. |
||
collisions |
Number of messages retransmitted because of an Ethernet collision. This is usually the result of an overextended LAN (Ethernet or transceiver cable too long, more than two repeaters between stations, or too many cascaded multiport transceivers). A packet that collides is counted only once in output packets. |
||
interface resets |
Number of times an interface has been completely reset. This can happen if packets queued for transmission were not sent within several seconds. Interface resets can occur when an interface is looped back or shut down. |
||
babbles |
Transmit jabber timer expired. |
||
late collision |
Number of late collisions. Late collision happens when a collision occurs after transmitting the preamble. |
||
deferred |
Number of times that the interface had to defer while ready to transmit a frame because the carrier was asserted. |
||
lost carrier |
Number of times the carrier was lost during transmission. |
||
no carrier |
Number of times the carrier was not present during the transmission.
|
||
output buffer failures, output buffers swapped out |
These counters are not used by the 2-Port 10/100/1000 Gigabit Ethernet SPA on the Cisco 7304 router. |
The following is sample output from the show interfaces pos command on a Cisco 7600 series router or Catalyst 6500 series switch for POS interface 4/3/0 (which is the interface for port 0 of the SPA in subslot 3 of the SIP in chassis slot 4):
Router# show interfaces pos 4/3/0 POS4/3/0 is up, line protocol is up (APS working - active) Hardware is Packet over SONET Internet address is 10.0.0.1/8 MTU 4470 bytes, BW 622000 Kbit, DLY 100 usec, rely 255/255, load 1/255 Encapsulation HDLC, crc 16, loopback not set Keepalive not set Scramble disabled Last input 00:00:34, output 04:09:06, output hang never Last clearing of "show interface" counters never Queueing strategy:fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops Available Bandwidth 622000 kilobits/sec 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 782 packets input, 226563 bytes, 0 no buffer Received 0 broadcasts, 1 runts, 0 giants, 0 throttles 0 parity 1 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 271 packets output, 28140 bytes, 0 underruns 0 output errors, 0 applique, 2 interface resets 0 output buffer failures, 0 output buffers swapped out 2 carrier transitions
The table below describes the significant fields shown in this display.
Field |
Description |
---|---|
POS4/3/0 is up, line protocol is up |
Indicates whether the interface hardware is currently active and can transmit and receive or whether it has been taken down by an administrator. |
Hardware is. . . |
Hardware type: |
Internet address is |
Internet address and subnet mask. |
MTU |
Maximum transmission unit of the interface. |
BW |
Bandwidth of the interface, in kilobits per second. |
DLY |
Delay of the interface, in microseconds. |
rely |
Reliability of the interface as a fraction of 255 (255/255 is 100 percent reliability), calculated as an exponential average over 5 minutes. |
load |
Load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes. The calculation uses the value from the bandwidth interface configuration command. |
Encapsulation |
Encapsulation method assigned to the interface. |
Loopback |
Indicates whether loopbacks are set. |
Keepalive |
Indicates whether keepalives are set. |
Scramble |
Indicates whether SONET payload scrambling is enabled. SONET scrambling is disabled by default. For the POS SPAs on the Cisco 12000 series routers, scrambling is enabled by default. |
Last input |
Number of hours, minutes, and seconds since the last packet was successfully received by an interface and processed locally on the router. Useful for knowing when a dead interface failed. This counter is updated only when packets are process-switched, not when packets are fast-switched. |
(Last) output |
Number of hours, minutes, and seconds since the last packet was successfully transmitted by an interface. This counter is updated only when packets are process-switched, not when packets are fast-switched. |
(Last) output hang |
Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the “last” fields exceeds 24 hours, the number of days and hours is printed. If that field overflows, asterisks are printed. |
Last clearing |
Time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared. *** indicates the elapsed time is too large to be displayed. 0:00:00 indicates the counters were cleared more than 2231 ms (and less than 232 ms) ago. |
Queueing strategy |
FIFO queueing strategy (other queueing strategies you might see are priority-list, custom-list, and weighted fair). |
Output queue, drops input queue, drops |
Number of packets in output and input queues. Each number is followed by a slash, the maximum size of the queue, and the number of packets dropped because a queue was full. |
5 minute input rate 5 minute output rate |
Average number of bits and packets received or transmitted per second in the last 5 minutes. |
packets input |
Total number of error-free packets received by the system. |
bytes (input) |
Total number of bytes, including data and MAC encapsulation, in the error-free packets received by the system. |
no buffer |
Number of received packets discarded because there was no buffer space in the main system. Compare with number of packets ignored. Broadcast storms on Ethernets and bursts of noise on serial lines are often responsible for no input buffer events. |
broadcasts |
Total number of broadcast or multicast packets received by the interface. |
runts |
Number of packets that are discarded because they are smaller than the minimum packet size of the medium. |
giants |
Number of packets that are discarded because they exceed the maximum packet size of the medium. |
throttles |
Not supported for POS interfaces. |
parity |
Report of the parity errors on the interface. |
input errors |
Total number of no buffer, runts, giants, CRCs, frame, overrun, ignored, and abort counts. Other input-related errors can also increment the count, so that this sum might not balance with the other counts. |
CRC |
Cyclic redundancy checksum generated by the originating LAN station or far-end device does not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRCs is usually the result of collisions or a station transmitting bad data. On a serial link, CRCs usually indicate noise, gain hits, or other transmission problems on the data link. |
frame |
Number of packets received incorrectly having a CRC error and a noninteger number of octets. On a serial line, this is usually the result of noise or other transmission problems. |
overrun |
Number of times the serial receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver’s ability to handle the data. |
ignored |
Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers mentioned previously in the buffer description. Broadcast storms and bursts of noise can cause the ignored count to be incremented. |
abort |
Illegal sequence of one bits on the interface. |
packets output |
Total number of messages transmitted by the system. |
bytes (output) |
Total number of bytes, including data and MAC encapsulation, transmitted by the system. |
underruns |
Number of times that the far-end transmitter has been running faster than the near-end router’s receiver can handle. |
output errors |
Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this might not balance with the sum of the enumerated output errors, because some datagrams can have more than one error, and others can have errors that do not fall into any of the specifically tabulated categories. |
applique |
Indicates an unrecoverable error has occurred on the POSIP applique. The system then invokes an interface reset. |
interface resets |
Number of times an interface has been completely reset. This can happen if packets queued for transmission were not sent within a certain interval. If the system notices that the carrier detect line of an interface is up, but the line protocol is down, it periodically resets the interface in an effort to restart it. Interface resets can also occur when an unrecoverable interface processor error occurred, or when an interface is looped back or shut down. |
output buffer failures |
Not supported for POS interfaces. |
output buffers swapped out |
Not supported for POS interfaces. |
carrier transitions |
Number of times the carrier detect signal of the interface has changed state. |
The following is sample output from the show interfaces pos command on a Cisco 12000 series router for POS interface 1/1/0 (which is the interface for port 0 of the SPA in subslot 1 of the SIP in chassis slot 1):
Router# show interfaces pos 1/1/0 POS1/1/0 is up, line protocol is up Hardware is Packet over SONET Internet address is 10.41.41.2/24 MTU 4470 bytes, BW 9952000 Kbit, DLY 100 usec, rely 255/255, load 1/255 Encapsulation HDLC, crc 32, loopback not set Keepalive not set Scramble enabled Last input 00:00:59, output 00:00:11, output hang never Last clearing of "show interface" counters 00:00:14 Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops Available Bandwidth 9582482 kilobits/sec 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 0 packets input, 0 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 parity 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 1 packets output, 314 bytes, 0 underruns 0 output errors, 0 applique, 0 interface resets 0 output buffer failures, 0 output buffers swapped out 0 carrier transitions
The following is sample output from the show interfaces sdcccommand on a Cisco 12000 series router for POS interface 1/1/0 (which is the interface for port 0 of the SPA in subslot 1 of the SIP in chassis slot 1):
Router# show interfaces sdcc 1/1/0 SDCC1/1/0 is administratively down, line protocol is down Hardware is SDCC MTU 1500 bytes, BW 192 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation HDLC, crc 32, loopback not set Keepalive set (10 sec) Last input never, output never, output hang never Last clearing of "show interface" counters 00:01:55 Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 0 packets input, 0 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 0 packets output, 0 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets 0 output buffer failures, 0 output buffers swapped out 0 carrier transitions
The table below describes the significant fields shown in the display.
Field |
Description |
---|---|
SDCC1/1/0 is administratively down, line protocol is down |
Indicates whether the interface hardware is currently active and can transmit and receive or whether it has been taken down by an administrator. |
Hardware is. . . |
Hardware type is SDCC--Section Data Communications Channel. |
Internet address is |
Internet address and subnet mask. |
MTU |
Maximum transmission unit of the interface. |
BW |
Bandwidth of the interface, in kilobits per second. |
DLY |
Delay of the interface, in microseconds. |
rely |
Reliability of the interface as a fraction of 255 (255/255 is 100 percent reliability), calculated as an exponential average over 5 minutes. |
load |
Load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes. The calculation uses the value from the bandwidth interface configuration command. |
Encapsulation |
Encapsulation method assigned to the interface. |
crc |
Cyclic redundancy check size (16 or 32 bits). |
Loopback |
Indicates whether loopback is set. |
Keepalive |
Indicates whether keepalives are set. |
Last input |
Number of hours, minutes, and seconds since the last packet was successfully received by an interface and processed locally on the router. Useful for knowing when a dead interface failed. This counter is updated only when packets are process-switched, not when packets are fast-switched. |
(Last) output |
Number of hours, minutes, and seconds since the last packet was successfully transmitted by an interface. This counter is updated only when packets are process-switched, not when packets are fast-switched. |
(Last) output hang |
Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the “last” fields exceeds 24 hours, the number of days and hours is printed. If that field overflows, asterisks are printed. |
Last clearing |
Time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared. *** indicates the elapsed time is too large to be displayed. 0:00:00 indicates the counters were cleared more than 2231 ms (and less than 232 ms) ago. |
Queueing strategy |
FIFO queueing strategy (other queueing strategies you might see are priority-list, custom-list, and weighted fair). |
Output queue, drops input queue, drops |
Number of packets in output and input queues. Each number is followed by a slash, the maximum size of the queue, and the number of packets dropped because a queue was full. |
5 minute input rate 5 minute output rate |
Average number of bits and packets received or transmitted per second in the last 5 minutes. |
packets input |
Total number of error-free packets received by the system. |
bytes (input) |
Total number of bytes, including data and MAC encapsulation, in the error-free packets received by the system. |
no buffer |
Number of received packets discarded because there was no buffer space in the main system. Compare with number of packets ignored. Broadcast storms on Ethernets and bursts of noise on serial lines are often responsible for no input buffer events. |
broadcasts |
Total number of broadcast or multicast packets received by the interface. |
runts |
Number of packets that are discarded because they are smaller than the minimum packet size of the medium. |
giants |
Number of packets that are discarded because they exceed the maximum packet size of the medium. |
throttles |
Not supported for POS interfaces. |
parity |
Report of the parity errors on the interface. |
input errors |
Total number of no buffer, runts, giants, CRCs, frame, overrun, ignored, and abort counts. Other input-related errors can also increment the count, so that this sum might not balance with the other counts. |
CRC |
Cyclic redundancy checksum generated by the originating LAN station or far-end device does not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRCs is usually the result of collisions or a station transmitting bad data. On a serial link, CRCs usually indicate noise, gain hits, or other transmission problems on the data link. |
frame |
Number of packets received incorrectly having a CRC error and a noninteger number of octets. On a serial line, this is usually the result of noise or other transmission problems. |
overrun |
Number of times the serial receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver’s ability to handle the data. |
ignored |
Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers mentioned previously in the buffer description. Broadcast storms and bursts of noise can cause the ignored count to be incremented. |
abort |
Illegal sequence of one bits on the interface. |
packets output |
Total number of messages transmitted by the system. |
bytes (output) |
Total number of bytes, including data and MAC encapsulation, transmitted by the system. |
underruns |
Number of times that the far-end transmitter has been running faster than the near-end router’s receiver can handle. |
output errors |
Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this might not balance with the sum of the enumerated output errors, because some datagrams can have more than one error, and others can have errors that do not fall into any of the specifically tabulated categories. |
collisions |
Not supported for POS interfaces. |
interface resets |
Number of times an interface has been completely reset. This can happen if packets queued for transmission were not sent within a certain interval. If the system notices that the carrier detect line of an interface is up, but the line protocol is down, it periodically resets the interface in an effort to restart it. Interface resets can also occur when an unrecoverable interface processor error occurred, or when an interface is looped back or shut down. |
output buffer failures |
Not supported for POS interfaces. |
output buffers swapped out |
Not supported for POS interfaces. |
carrier transitions |
Number of times the carrier detect signal of the interface has changed state. |
The following example shows the interface serial statistics on the first port of a T3/E3 SPA installed in subslot 0 of the SIP located in chassis slot 5:
Router# show interfaces serial 5/0/0 Serial5/0/0 is up, line protocol is up Hardware is SPA-4T3E3 Internet address is 10.1.1.2/24 MTU 4470 bytes, BW 44210 Kbit, DLY 200 usec, reliability 255/255, txload 234/255, rxload 234/255 Encapsulation HDLC, crc 16, loopback not set Keepalive set (10 sec) Last input 00:00:05, output 00:00:00, output hang never Last clearing of "show interface" counters never Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 40685000 bits/sec, 115624 packets/sec 5 minute output rate 40685000 bits/sec, 115627 packets/sec 4653081241 packets input, 204735493724 bytes, 0 no buffer Received 4044 broadcasts (0 IP multicast) 0 runts, 0 giants, 0 throttles 0 parity 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 4652915555 packets output, 204728203520 bytes, 0 underruns 0 output errors, 0 applique, 4 interface resets 0 output buffer failures, 0 output buffers swapped out 2 carrier transitions
The table below describes the fields shown in the show interfaces serial output for a T3/E3 SPA.
Note | The fields appearing in the ouput will vary depending on card type, interface configuration, and the status of the interface. |
Field |
Description |
---|---|
Serial |
Name of the serial interface. |
line protocol is |
If the line protocol is up, the local router has received keepalive packets from the remote router. If the line protocol is down, the local router has not received keepalive packets form the remote router. |
Hardware is |
Designates the specific hardware type of the interface. |
Internet address is |
The IP address of the interface. |
MTU |
The maximum packet size set for the interface. |
BW |
Bandwidth in kilobits per second. |
DLY |
Interface delay in microseconds. |
reliability |
Reliability of the interface as a fraction of 255 (255/255 is 100 percent reliability), calculated as an exponential average over 5 minutes. |
txload |
Transmit load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes. |
rxload |
Receive load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes. |
Encapsulation |
Encapsulation method. |
crc |
CRC size in bits. |
loopback |
Indicates whether loopback is set. |
keepalive |
Indicates whether keepalives are set. |
Last input |
Number of hours, minutes, and seconds since the last packet was successfully received by an interface and processed locally on the router. Useful for knowing when a dead interface failed. This counter is updated only when packets are process-switched, not when packets are fast-switched. |
Last output |
Number of hours, minutes, and seconds since the last packet was successfully transmitted by an interface. Useful for knowing when a dead interface failed. This counter is updated only when packets are process-switched, not when packets are fast-switched. |
output hang |
Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the “last” fields exceeds 24 hours, the number of days and hours is printed. If that field overflows, asterisks are printed. |
Last clearing of show interface counters |
Time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared. *** indicates the elapsed time is too large to be displayed. 0:00:00 indicates the counters were cleared more than 231 milliseconds (and less than 232 ms) ago. |
Input queue |
Packet statistics on the input queue reported as: |
Total output drops |
Total number of dropped packets. |
Queueing strategy |
FIFO queueing strategy (other queueing strategies you might see are priority-list, custom-list, and weighted fair). |
Output queue |
Number of packets in the output queue (size), and the maximum size of the queue (max). |
5-minute input rate |
Average number of bits and packets received per second in the last 5 minutes. If the interface is not in promiscuous mode, it senses network traffic it sends and receives (rather than all network traffic). The 5-minute input and output rates should be used only as an approximation of traffic per second during a given 5-minute period. These rates are exponentially weighted averages with a time constant of 5 minutes. A period of four time constants must pass before the average will be within two percent of the instantaneous rate of a uniform stream of traffic over that period. |
5-minute output rate |
Average number of bits and packets transmitted per second in the last 5 minutes. If the interface is not in promiscuous mode, it senses network traffic it sends and receives (rather than all network traffic). The 5-minute input and output rates should be used only as an approximation of traffic per second during a given 5-minute period. These rates are exponentially weighted averages with a time constant of 5 minutes. A period of four time constants must pass before the average will be within two percent of the instantaneous rate of a uniform stream of traffic over that period. |
The following is sample output from the show interfaces tengigabitethernet command for the only interface (port 0) in a 1-Port 10 Gigabit Ethernet SPA located in the top subslot (0) of the carrier card that is installed in slot 7 on a Cisco 12000 series router:
Router# show interfaces tengigabitethernet 7/0/0 TenGigabitEthernet7/0/0 is up, line protocol is up (connected) Hardware is TenGigEther SPA, address is 0000.0c00.0102 (bia 000f.342f.c340) Internet address is 10.1.1.2/24 MTU 1500 bytes, BW 10000000 Kbit, DLY 10 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive not supported Full-duplex, 10Gb/s input flow-control is on, output flow-control is on ARP type: ARPA, ARP Timeout 04:00:00 Last input never, output 00:00:10, output hang never Last clearing of "show interface" counters 20:24:30 Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec L2 Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes L3 in Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes mcast L3 out Switched: ucast: 0 pkt, 0 bytes mcast: 0 pkt, 0 bytes 237450882 packets input, 15340005588 bytes, 0 no buffer Received 25 broadcasts (0 IP multicasts) 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 0 multicast, 0 pause input 0 input packets with dribble condition detected 1676 packets output, 198290 bytes, 0 underruns 0 output errors, 0 collisions, 4 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier, 0 PAUSE output 0 output buffer failures, 0 output buffers swapped out
The table below describes the significant fields shown in the display.
Field |
Description |
---|---|
TenGigabitEthernet...is up ...is administratively down |
Indicates whether the interface hardware is currently active and if it has been taken down by an administrator. |
line protocol is |
Indicates whether the software processes that handle the line protocol consider the line usable or if it has been taken down by an administrator. |
Hardware |
Hardware type and MAC address. |
Description |
Alphanumeric string identifying the interface. This appears only if the description interface configuration command has been configured on the interface. |
Internet address |
Internet address followed by subnet mask. |
MTU |
Maximum transmission unit of the interface. |
BW |
Bandwidth of the interface in kilobits per second. |
DLY |
Delay of the interface in microseconds. |
reliability |
Reliability of the interface as a fraction of 255 (255/255 is 100 percent reliability), calculated as an exponential average over 5 minutes. |
txload, rxload |
Load on the interface (in the transmit “tx” and receive “rx” directions) as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes. |
Encapsulation |
Encapsulation method assigned to the interface. |
loopback |
Indicates whether loopback is set. |
Keepalive |
Indicates whether keepalives are set, and the time interval. |
Half-duplex, Full-duplex |
Indicates the duplex mode for the interface. |
10Gb/s |
Speed of the interface in Gigabits per second. |
input flow control ... |
Specifies if input flow control is on or off. |
ARP type: |
Type of ARP assigned and the timeout period. |
Last input |
Number of hours, minutes, and seconds since the last packet was successfully received by an interface and processed locally on the router. Useful for knowing when a dead interface failed. This field is not updated by fast-switched traffic. |
output |
Number of hours, minutes, and seconds since the last packet was successfully transmitted by the interface. Useful for knowing when a dead interface failed. |
output hang |
Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the “last” fields exceeds 24 hours, the number of days and hours is displayed. If that field overflows, asterisks are printed. |
Last clearing |
Time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared. A series of asterisks (***) indicates the elapsed time is too large to be displayed. 0:00:00 indicates the counters were cleared more than 231 ms (and less than 232 ms) ago. |
Input queue (size/max/drops/flushes) |
Packet statistics on the input queue reported as:
|
Total output drops |
Total number of packets dropped because of a full output queue. |
Queueing strategy |
Type of Layer 3 queueing active on this interface. The default is FIFO. |
Output queue (size/max) |
Number of packets in the output queue (size), and the maximum size of the queue (max). |
5 minute input rate, 5 minute output rate |
Average number of bits and packets transmitted per second in the last 5 minutes. If the interface is not in promiscuous mode, it senses network traffic it sends and receives (rather than all network traffic). The 5-minute input and output rates should be used only as an approximation of traffic per second during a given 5-minute period. These rates are exponentially weighted averages with a time constant of 5 minutes. A period of four time constants must pass before the average will be within two percent of the instantaneous rate of a uniform stream of traffic over that period. |
L2 Switched |
Provides statistics about Layer 2 switched traffic, including unicast and multicast traffic. |
L3 in Switched |
Provides statistics about received Layer 3 traffic. |
L3 out Switched |
Provides statistics about sent Layer 3 traffic. |
packets input |
Total number of error-free packets received by the system. |
bytes |
Total number of bytes, including data and MAC encapsulation, in the error-free packets received by the system. |
Received...broadcasts |
Total number of broadcast or multicast packets received by the interface. |
runts |
Number of packets that are discarded because they are smaller than the minimum packet size of the medium. |
giants |
Number of packets that are discarded because they exceed the maximum packet size of the medium. |
throttles |
Number of times the receiver on the port was disabled, possibly because of buffer or processor overload. |
input errors |
Includes runts, giants, no buffer, CRC, frame, overrun, and ignored counts. Other input-related errors can also cause the input errors count to be increased, and some datagrams may have more than one error; therefore, this sum may not balance with the sum of enumerated input error counts. |
CRC |
Cyclic redundancy check generated by the originating LAN station or far-end device does not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRCs is usually the result of collisions or a station transmitting bad data. |
frame |
Number of packets received incorrectly having a CRC error and a noninteger number of octets. On a LAN, this is usually the result of collisions or a malfunctioning Ethernet device. |
overrun |
Number of times the receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver’s ability to handle the data. |
ignored |
Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers. Broadcast storms and bursts of noise can cause the ignored count to be increased. |
watchdog |
Number of times the watchdog receive timer expired. |
multicast |
Number of multicast packets. |
pause input |
Number of pause packets received. |
input packets with dribble condition detected |
Dribble bit error indicates that a frame is slightly too long. This frame error counter is incremented for informational purposes only; the router accepts the frame. |
packets output |
Total number of messages transmitted by the system. |
bytes |
Total number of bytes, including data and MAC encapsulation, transmitted by the system. |
underruns |
Number of times that the transmitter has been running faster than the router can handle. |
output errors |
Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this may not balance with the sum of the enumerated output errors, because some datagrams may have more than one error and others may have errors that do not fall into any of the specifically tabulated categories. |
collisions |
Number of messages retransmitted because of an Ethernet collision. This is usually the result of an overextended LAN (Ethernet or transceiver cable too long, more than two repeaters between stations, or too many cascaded multiport transceivers). A packet that collides is counted only once in output packets. |
interface resets |
Number of times an interface has been completely reset. This can happen if packets queued for transmission were not sent within several seconds. Interface resets can occur when an interface is looped back or shut down. |
babbles |
Transmit jabber timer expired. |
late collision |
Number of late collisions. Late collision happens when a collision occurs after transmitting the preamble. |
deferred |
Number of times that the interface had to defer while ready to transmit a frame because the carrier was asserted. |
lost carrier |
Number of times the carrier was lost during transmission. |
no carrier |
Number of times the carrier was not present during the transmission. |
pause output |
Number of pause packets transmitted. |
output buffer failures, output buffers swapped out |
Number of output butters failures and output buffers swapped out. |
This example shows how to display traffic for a specific interface:
Router# show interfaces GigabitEthernet1/1 GigabitEthernet0/1 is up, line protocol is up Hardware is BCM1125 Internal MAC, address is 0016.9de5.d9d1 (bia 0016.9de5.d9d1) Internet address is 172.16.165.40/27 MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Full-duplex, 100Mb/s, media type is RJ45 output flow-control is XON, input flow-control is XON ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:00:11, output 00:00:08, output hang never Last clearing of "show interface" counters never Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 10 packets input, 2537 bytes, 0 no buffer Received 10 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 46 multicast, 0 pause input 0 input packets with dribble condition detected 18 packets output, 3412 bytes, 0 underruns 0 output errors, 0 collisions, 1 interface resets 7 unknown protocol drops 0 babbles, 0 late collision, 0 deferred 2 lost carrier, 0 no carrier, 0 pause output 0 output buffer failures, 0 output buffers swapped out
Note | The unknown protocol drops field displayed in the above example refers to the total number of packets dropped due to unknown or unsupported types of protocol. This field occurs on several platforms such as the Cisco 3725, 3745, 3825, and 7507 series routers. |
This example shows how to display traffic for a FlexWAN module:
Router# show interfaces pos 6/1/0.1 POS6/1/0.1 is up, line protocol is up Hardware is Packet over Sonet Internet address is 10.1.2.2/24 MTU 4470 bytes, BW 155000 Kbit, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation FRAME-RELAY <<<+++ no packets info after this line Arches#sh mod 6 Mod Ports Card Type Model Serial No. --- ----- -------------------------------------- ------------------ ----------- 6 0 2 port adapter FlexWAN WS-X6182-2PA SAD04340JY3 Mod MAC addresses Hw Fw Sw Status --- ---------------------------------- ------ ------------ ------------ ------- 6 0001.6412.a234 to 0001.6412.a273 1.3 12.2(2004022 12.2(2004022 Ok Mod Online Diag Status --- ------------------- 6 Pass Router#
Command |
Description |
---|---|
fair-queue |
Enables WFQ. |
interface |
Configures an interface type and enters interface configuration mode. |
show controllers fastethernet |
Displays Fast Ethernet interface information, transmission statistics and errors, and applicable MAC destination address and VLAN filtering tables. |
show controllers gigabitethernet |
Displays Gigabit Ethernet interface information, transmission statistics and errors, and applicable MAC destination address and VLAN filtering tables. |
show controllers pos |
Displays information about the POS controllers. |
show controllers serial |
Displays controller statistics. |
To display the information about the Fast EtherChannel on Cisco 7000 series routers with the RSP7000 and RSP7000CI, Cisco 7200 series routers, and Cisco 7500 series routers, use the showinterfacesport-channel command in user EXEC or privileged EXEC mode.
show interfaces port-channel commandshow interfaces port-channel [channel-number]
channel-number |
(Optional) Port channel number. Range is from 1 to 4. |
User EXEC Privileged EXEC
Release |
Modification |
---|---|
11.1 CA |
This command was introduced. |
12.1(5)T |
This command was integrated into Cisco IOS Release 12.1(5)T. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
12.2SX |
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware. |
15.2(02)SA |
This command was implemented on the Cisco ME 2600X Series Ethernet Access Switches. |
The following is sample output from the showinterfacesport-channel command:
Note | By default the hardware type is set to Fast EtherChannel.The default MTU is set to 1500 bytes. The maximum MTU size that can be configured on the native Gigabit Ethernet ports on the Cisco 7200 series router is 9216. The range of configurable MTU value is from 1500 to 9216. |
Router# show interfaces port-channel 1 Port-channel1 is up, line protocol is up Hardware is FEChannel, address is 0000.0ca8.6220 (bia 0000.0000.0000) MTU 1500 bytes, BW 400000 Kbit, DLY 100 usec, rely 255/255, load 1/255 Encapsulation ARPA, loopback not set, keepalive not set, fdx ARP type: ARPA, ARP Timeout 04:00:00 No. of active members in this channel: 4 Member 0 : Fast Ethernet1/0/0 Member 1 : Fast Ethernet1/1/0 Member 2 : Fast Ethernet4/0/0 Member 3 : Fast Ethernet4/1/0 Last input 01:22:13, output never, output hang never Last clearing of “show interface” counters never Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 223 packets input, 11462 bytes, 0 no buffer Received 1 broadcasts, 0 runts, 0 giants 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 0 watchdog, 0 multicast 0 input packets with dribble condition detected 192 packets output, 13232 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out
The following sample output from the showinterfacesport-channel shows Gigabit EtherChannel as hardware type and the MTU value as 9216:
Router# show interface port-channel 1 Port-channel1 is up, line protocol is up Hardware is GEChannel , address is 0001.c929.c41b (bia 0001.c929.c41b) MTU 9216 bytes , BW 1000000 Kbit, DLY 10 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Unknown duplex, Unknown Speed, media type is unknown media type output flow-control is unsupported, input flow-control is unsupported ARP type: ARPA, ARP Timeout 04:00:00 No. of active members in this channel: 1 Member 0 : GigabitEthernet0/1 , Full-duplex, 1000Mb/s No. of Non-active members in this channel: 0 Last input 00:00:04, output never, output hang never Last clearing of "show interface" counters never Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 95 packets input, 34383 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 0 multicast, 0 pause input 0 input packets with dribble condition detected 1 packets output, 77 bytes, 0 underruns 2 output errors, 0 collisions, 0 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier, 0 pause output 0 output buffer failures, 0 output buffers swapped out
The table below describes significant fields shown in the display.
Field |
Description |
---|---|
Port-channel1 is up, line protocol is up |
Indicates if the interface hardware is currently active and can transmit and receive or if it has been taken down by an administrator. |
Hardware is |
Hardware type (Fast EtherChannel). |
address is |
Address being used by the interface. |
MTU |
Maximum transmission unit of the interface. |
BW |
Bandwidth of the interface, in kilobits per second. |
DLY |
Delay of the interface, in microseconds. |
rely |
Reliability of the interface as a fraction of 255 (255/255 is 100 percent reliability), calculated as an exponential average over 5 minutes. |
load |
Load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes. The calculation uses the value from the bandwidth interface configuration command. |
Encapsulation |
Encapsulation method assigned to the interface. |
loopback |
Indicates if loopbacks are set. |
keepalive |
Indicates if keepalives are set. |
fdx |
Indicates the interface is operating in full-duplex mode. |
ARA type |
ARP type on the interface. |
ARP timeout |
Number of hours, minutes, and seconds an ARP cache entry will stay in the cache. |
No. of active members in this channel: 4 |
Number of Fast Ethernet interfaces that are currently active (not down) and part of the Fast EtherChannel group. |
Member 0: Fast Ethernet1/0/0 |
Specific Fast Ethernet interface that is part of the Fast EtherChannel group. |
Last input |
Number of hours, minutes, and seconds since the last packet was successfully received by an interface and processed locally on the router. Useful for knowing when a dead interface failed. This counter is updated only when packets are process-switched, not when packets are fast-switched. |
output |
Number of hours, minutes, and seconds since the last packet was successfully transmitted by an interface. This counter is updated only when packets are process-switched, not when packets are fast-switched. |
output hang |
Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the “last” fields exceeds 24 hours, the number of days and hours is printed. If that field overflows, asterisks are printed. |
last clearing |
Time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared. *** indicates the elapsed time is too large to be displayed. 0:00:00 indicates the counters were cleared more than 231 ms (and less than 232 ms)) ago. |
Queueing strategy |
First-in, first-out queueing strategy (other queueing strategies you might see are priority-list, custom-list, and weighted fair). |
Output queue, drops input queue, drops |
Number of packets in output and input queues. Each number is followed by a slash, the maximum size of the queue, and the number of packets dropped because a queue was full. |
5 minute input rate 5 minute output rate |
Average number of bits and packets received or transmitted per second in the last 5 minutes. |
packets input |
Total number of error-free packets received by the system. |
bytes (input) |
Total number of bytes, including data and MAC encapsulation, in the error-free packets received by the system. |
no buffer |
Number of received packets discarded because there was no buffer space in the main system. Compare with ignored count. Broadcast storms on Ethernets and bursts of noise on serial lines are often responsible for no input buffer events. |
broadcasts |
Total number of broadcast or multicast packets received by the interface. |
runts |
Number of packets that are discarded because they are smaller than the minimum packet size of the medium. |
giants |
Number of packets that are discarded because they exceed the maximum packet size of the medium. |
input errors |
Total number of no buffer, runts, giants, CRCs, frame, overrun, ignored, and abort counts. Other input-related errors can also increment the count, so that this sum might not balance with the other counts. |
CRC |
Cyclic redundancy checksum generated by the originating LAN station or far-end device does not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRCs is usually the result of collisions or a station transmitting bad data. On a serial link, CRCs usually indicate noise, gain hits or other transmission problems on the data link. |
frame |
Number of packets received incorrectly having a CRC error and a noninteger number of octets. On a serial line, this is usually the result of noise or other transmission problems. |
overrun |
Number of times the serial receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver’s ability to handle the data. |
ignored |
Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers mentioned previously in the buffer description. Broadcast storms and bursts of noise can cause the ignored count to be incremented. |
abort |
Illegal sequence of ones bit on the interface. |
watchdog |
Number of times watchdog receive timer expired. It happens when receiving a packet with length greater than 2048. |
multicast |
Number of multicast packets received. |
input packets with dribble condition detected |
Dribble bit error indicates that a frame is slightly too long. This frame error counter is incremented just for informational purposes; the router accepts the frame. |
packets output |
Total number of messages transmitted by the system. |
bytes (output) |
Total number of bytes, including data and MAC encapsulation, transmitted by the system. |
underruns |
Number of times that the far-end transmitter has been running faster than the near-end router’s receiver can handle. |
output errors |
Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this might not balance with the sum of the enumerated output errors, as some datagrams can have more than one error, and others can have errors that do not fall into any of the specifically tabulated categories. |
collisions |
Number of messages retransmitted because of an Ethernet collision. A packet that collides is counted only once in output packets. |
interface resets |
Number of times an interface has been completely reset. This can happen if packets queued for transmission were not sent within a certain interval. If the system notices that the carrier detect line of an interface is up, but the line protocol is down, it periodically resets the interface in an effort to restart it. Interface resets can also occur when an unrecoverable interface processor error occurred, or when an interface is looped back or shut down. |
babbles |
The transmit jabber timer expired. |
late collision |
Number of late collisions. Late collision happens when a collision occurs after transmitting the preamble. The most common cause of late collisions is that your Ethernet cable segments are too long for the speed at which you are transmitting. |
deferred |
Deferred indicates that the chip had to defer while ready to transmit a frame because the carrier was asserted. |
lost carrier |
Number of times the carrier was lost during transmission. |
no carrier |
Number of times the carrier was not present during the transmission. |
output buffer failures |
Number of times that a packet was not output from the output hold queue because of a shortage of MEMD shared memory. |
output buffers swapped out |
Number of packets stored in main memory when the output queue is full; swapping buffers to main memory prevents packets from being dropped when output is congested. The number is high when traffic is bursty. |
Command |
Description |
---|---|
interface multilink |
Specifies a Fast EtherChannel and enters interface configuration mode. |
To display the protocols that are tunneled on an interface or on all interfaces, use the showl2protocol-tunnel command.
show l2protocol-tunnel [ interface interface mod /port | summary | vlan vlan ]
interface interface-id |
(Optional) Specifies the interface type; possible valid values are ethernet, FastEthernet, gigabitethernet, tengigabitethernet, pos, atm, and ge-wan |
mod/port |
Module and port number. |
summary |
(Optional) Displays a summary of a tunneled port. |
vlanvlan |
(Optional) Limits the display to interfaces on the specified VLAN. Valid values are from 1 to 4094. |
EXEC (>)
Privileged EXEC (#)
Release |
Modification |
---|---|
12.2(14)SX |
Support for this command was introduced on the Supervisor Engine 720. |
12.2(17a)SX |
The showl2protocol-tunnelsummary command output was changed to display the following information: |
12.2(17d)SXB |
Support for this command on the Supervisor Engine 2 was extended to the 12.2 SX release. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
12.2(33)SXI |
This command was changed to add the optional vlanvlan keyword and argument. |
15.2(2)T |
This command was integrated into Cisco IOS Release 15.2(2)T. |
After enabling Layer 2 protocol tunneling on an access or IEEE 802.1Q tunnel port by using the l2protocol-tunnel interface configuration command, you can configure some or all of these parameters:
The showl2protocol-tunnel command displays only the ports that have protocol tunneling enabled.
The showl2protocol-tunnelsummary command displays the ports that have protocol tunneling enabled, regardless of whether the port is down or currently configured as a trunk.
The following example is an output from the show l2protocol-tunnel command:
Router# show l2protocol-tunnel COS for Encapsulated Packets: 5 Drop Threshold for Encapsulated Packets: 0
Port |
Protocol |
Shutdown Threshold |
Drop Threshold |
Encapsulation Counter |
Decapsulation Counter |
Drop Counter |
Fa0/3 |
--- |
---- |
---- |
---- |
---- |
---- |
--- |
---- |
---- |
---- |
---- |
---- |
|
--- |
---- |
---- |
---- |
---- |
---- |
|
pagp |
---- |
---- |
0 |
242500 |
||
lacp |
---- |
---- |
24268 |
242640 |
||
udld |
---- |
---- |
0 |
897960 |
||
Fa0/4 |
--- |
---- |
---- |
---- |
---- |
---- |
--- |
---- |
---- |
---- |
---- |
---- |
|
--- |
---- |
---- |
---- |
---- |
---- |
|
pagp |
1000 |
---- |
24249 |
242700 |
||
lacp |
---- |
---- |
24256 |
242660 |
||
udld |
---- |
---- |
0 |
1344820 |
||
Gi0/3 |
cdp |
---- |
---- |
134482 |
1344820 |
|
--- |
---- |
---- |
---- |
---- |
---- |
|
--- |
---- |
---- |
---- |
---- |
---- |
|
pagp |
1000 |
---- |
0 |
242500 |
||
lacp |
500 |
---- |
0 |
485320 |
||
udld |
300 |
---- |
44899 |
448980 |
||
Gi0/3 |
cdp |
---- |
---- |
134482 |
1344820 |
|
--- |
---- |
---- |
---- |
---- |
---- |
|
--- |
---- |
---- |
---- |
---- |
---- |
|
pagp |
---- |
1000 |
0 |
242700 |
||
lacp |
---- |
---- |
0 |
485220 |
||
udld |
300 |
---- |
44899 |
448980 |
This example shows how to display a summary of Layer 2-protocol tunnel ports:
Router# show l2protocol-tunnel summary COS for Encapsulated Packets:5 Drop Threshold for Encapsulated Packets:0 Port Protocol Shutdown Drop Status Threshold Threshold (cdp/stp/vtp) (cdp/stp/vtp) ------- ----------- ---------------- ---------------- ---------- Fa9/1 --- stp --- ----/----/---- ----/----/---- down Fa9/9 cdp stp vtp ----/----/---- ----/----/---- up Fa9/47 --- --- --- ----/----/---- 1500/1500/1500 down(trunk) Fa9/48 cdp stp vtp ----/----/---- ----/----/---- down(trunk)
This example shows how to display Layer 2-protocol tunnel information on interfaces for a specific VLAN:
Router# show l2protocol-tunnel vlan 1 COS for Encapsulated Packets: 5 Drop Threshold for Encapsulated Packets: 0 Protocol Drop Counter -------- ------------- cdp 0 lldp 0 stp 0 vtp 0 Port Protocol Thresholds Counters Shutdown Drop Encap Decap Drop ------------------- -------- --------- --------- --------- --------- ---------
Command |
Description |
---|---|
debug l2protocol-tunnel |
Displays the debugging options for L2PT. |
l2protocol-tunnel |
Enables the protocol tunneling on an interface and specifies the type of protocol to be tunneled. |
l2protocol-tunnel drop-threshold |
Specifies the maximum number of packets that can be processed for the specified protocol on that interface before being dropped. |
l2protocol-tunnel global drop-threshold |
Enables rate limiting at the software level. |
l2protocol-tunnel shutdown-threshold |
Specifies the maximum number of packets that can be processed for the specified protocol on that interface in 1 second. |
To display Link Aggregation Control Protocol (LACP) and multi-chassis LACP (mLACP) information, use the show lacp command in either user EXEC or privileged EXEC mode.
show lacp { channel-group-number { counters | internal [detail] | neighbor [detail] } | multi-chassis [load-balance] { group number | port-channel number } | sys-id }
show lacp { channel-group-number { counters | internal [detail] | neighbor [detail] | sys-id } }
channel-group- number |
(Optional) Number of the channel group. The following are valid values: |
counters |
Displays information about the LACP traffic statistics. |
internal |
Displays LACP internal information. |
neighbor |
Displays information about the LACP neighbor. |
detail |
(Optional) Displays detailed internal information when used with the internal keyword and detailed LACP neighbor information when used with the neighbor keyword. |
multi-chassis |
Displays information about mLACP. |
load-balance |
Displays mLACP load balance information. |
group |
Displays mLACP redundancy group information, |
number |
Integer value used with the group and port-channel keywords. |
port-channel |
Displays mLACP port-channel information. |
sys-id |
Displays the LACP system identification. It is a combination of the port priority and the MAC address of the device |
User EXEC (>) Privileged EXEC (#)
Release |
Modification |
---|---|
12.2(14)SX |
Support for this command was introduced on the Supervisor Engine 720. |
12.2(17d)SXB |
Support for this command on the Supervisor Engine 2 was extended to Cisco IOS Release 12.2(17d)SXB. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
12.2(31)SB2 |
This command was integrated into Cisco IOS Release 12.2(31)SB2. |
12.2(33)SRB |
Support for this command on the Cisco 7600 router was integrated into Cisco IOS Release 12.2(33)SRB. |
Cisco IOS XE Release 2.4 |
This command was integrated into Cisco IOS XE Release 2.4. |
12.2(33)SRE |
This command was modified. The multi-chassis, group, and port-channelkeywords and number argument were added. |
15.1(3)S |
This command was modified. The load-balance keyword was added. |
15.1(2)SNG |
This command was implemented on the Cisco ASR 901 Series Aggregation Services Router. |
Use the show lacp command to troubleshoot problems related to LACP in a network.
If you do not specify a value for the argument channel-group-number, all channel groups are displayed. Values in the range of 257 to 282 are supported on the CSM and the FWSM only.
This example shows how to display the LACP system identification using the show lacp sys-idcommand:
Device> show lacp sys-id 8000,AC-12-34-56-78-90
The system identification is made up of the system priority and the system MAC address. The first two bytes are the system priority, and the last six bytes are the globally administered individual MAC address that is associated to the system.
This example shows how to display the LACP statistics for a specific channel group:
Device# show lacp 1 counters LACPDUs Marker LACPDUs Port Sent Recv Sent Recv Pkts Err --------------------------------------------------- Channel group: 1 Fa4/1 8 15 0 0 3 0 Fa4/2 14 18 0 0 3 0 Fa4/3 14 18 0 0 0 Fa4/4 13 18 0 0 0
The output displays the following information:
The LACPDUs Sent and Recv columns display the LACPDUs that are sent and received on each specific interface.
The LACPDUs Pkts and Err columns display the marker-protocol packets.
The following example shows output from a show lacpchannel-group-numbercounterscommand:
Device1# show lacp 5 counters LACPDUs Marker Marker Response LACPDUs Port Sent Recv Sent Recv Sent Recv Pkts Err --------------------------------------------------------------------- Channel group: 5 Gi5/0/0 21 18 0 0 0 0 0
The following table describes the significant fields shown in the display.
Field |
Description |
---|---|
LACPDUs Sent Recv |
Number of LACP PDUs sent and received. |
Marker Sent Recv |
Attempts to avoid data loss when a member link is removed from an LACP bundle. |
Marker Response Sent Recv |
Cisco IOS response to the Marker protocol. |
LACPDUs Pkts Err |
Number of LACP PDU packets transmitted and the number of packet errors. |
The following example shows output from a show lacp internalcommand:
Device1# show lacp 5 internal Flags: S - Device is requesting Slow LACPDUs F - Device is requesting Fast LACPDUs A - Device is in Active mode P - Device is in Passive mode Channel group 5 LACP port Admin Oper Port Port Port Flags State Priority Key Key Number State Gi5/0/0 SA bndl 32768 0x5 0x5 0x42 0x3D
The following table describes the significant fields shown in the display.
Field |
Description |
---|---|
Flags |
Meanings of each flag value, which indicates a device activity. |
Port |
Port on which link bundling is configured. |
Flags |
Indicators of device activity. |
State |
Activity state of the port. States can be any of the following:
|
LACP port Priority |
Priority assigned to the port. |
Admin Key |
Defines the ability of a port to aggregate with other ports. |
Oper Key |
Determines the aggregation capability of the link. |
Port Number |
Number of the port. |
Port State |
State variables for the port that are encoded as individual bits within a single octet with the following meaning: |
This example shows how to display internal information for the interfaces that belong to a specific channel:
Device# show lacp 1 internal Flags: S - Device sends PDUs at slow rate. F - Device sends PDUs at fast rate. A - Device is in Active mode. P - Device is in Passive mode. Channel group 1 LACPDUs LACP Port Admin Oper Port Port Port Flags State Interval Priority Key Key Number State Fa4/1 saC bndl 30s 32768 100 100 0xc1 0x75 Fa4/2 saC bndl 30s 32768 100 100 0xc2 0x75 Fa4/3 saC bndl 30s 32768 100 100 0xc3 0x75 Fa4/4 saC bndl 30s 32768 100 100 0xc4 0x75 Device#
The following table describes the significant fields shown in the display.
Field |
Description |
---|---|
State |
Current state of the port; allowed values are as follows:
|
LACPDUs Interval |
Interval setting. |
LACP Port Priority |
Port-priority setting. |
Admin Key |
Defines the ability of a port to aggregate with other ports. |
Oper Key |
Determines the aggregation capability of the link. |
Port Number |
Port number. |
Port State |
Activity state of the port. |
This example shows how to display the information about the LACP neighbors for a specific port channel:
Device# show lacp 1 neighbors Flags: S - Device sends PDUs at slow rate. F - Device sends PDUs at fast rate. A - Device is in Active mode. P - Device is in Passive mode. Channel group 1 neighbors Partner Partner Port System ID Port Number Age Flags Fa4/1 8000,00b0.c23e.d84e 0x81 29s P Fa4/2 8000,00b0.c23e.d84e 0x82 0s P Fa4/3 8000,00b0.c23e.d84e 0x83 0s P Fa4/4 8000,00b0.c23e.d84e 0x84 0s P Port Admin Oper Port Priority Key Key State Fa4/1 32768 200 200 0x81 Fa4/2 32768 200 200 0x81 Fa4/3 32768 200 200 0x81 Fa4/4 32768 200 200 0x81 Device#
The following table describes the significant fields shown in the display.
Field |
Description |
---|---|
Port |
Port on which link bundling is configured. |
Partner System ID |
Peer’s LACP system identification (sys-id). It is a combination of the system priority and the MAC address of the peer device. |
Partner Port Number |
Port number on the peer device |
Age |
Number of seconds since the last LACP PDU was received on the port. |
Flags |
Indicators of device activity. |
Port Priority |
Port priority setting. |
Admin Key |
Defines the ability of a port to aggregate with other ports. |
Oper Key |
Determines the aggregation capability of the link. |
Port State |
Activity state of the port. See the Port State description in the show lacp internal Field Descriptions table for state variables. |
If no PDUs have been received, the default administrative information is displayed in braces.
Command |
Description |
---|---|
clear lacp counters |
Clears the statistics for all interfaces belonging to a specific channel group. |
lacp port-priority |
Sets the priority for the physical interfaces. |
lacp system-priority |
Sets the priority of the system. |
To display the link-state group information., use the showlinkstategroup command in user EXEC or privileged EXEC mode .
show link state group detail
detail |
Displays the detailed information about the group. |
Privileged EXEC (#)
Release |
Modification |
---|---|
15.1(1)S |
This command was introduced. |
Link State Ttracking (LST), also known as trunk failover, is a feature that binds the link state of multiple interfaces. When you configure LST for the first time, add upstream interfaces to the link state group before adding the downstream interface, otherwise the downstream interfaces would move into error-disable mode. The maximum number of link state groups configurable is 10.
The following example displays the link-state group information:
Router# enable Router# show link state group 1 Link State Group: 1 Status: Enabled, Down Router> show link state group detail (Up):Interface up (Dwn):Interface Down (Dis):Interface disabled Link State Group: 1 Status: Enabled, Down Upstream Interfaces : Gi3/5(Dwn) Gi3/6(Dwn) Downstream Interfaces : Gi3/1(Dis) Gi3/2(Dis) Gi3/3(Dis) Gi3/4(Dis) Link State Group: 2 Status: Enabled, Down Upstream Interfaces : Gi3/15(Dwn) Gi3/16(Dwn) Gi3/17(Dwn) Downstream Interfaces : Gi3/11(Dis) Gi3/12(Dis) Gi3/13(Dis) Gi3/14(Dis) (Up):Interface up (Dwn):Interface Down (Dis):Interface disabled
Command |
Description |
---|---|
link state track |
Configures the link state tracking number. |
link state group |
Configures the link state group and interface, as either an upstream or downstream interface in the group. |
To display dynamic MAC address table entries only, use the showmac-address-tabledynamic command in privileged EXEC mode.
show mac-address-table dynamic [ address mac-addr | interface interface type slot/number | vlan vlan ]
show mac-address-table dynamic [ address mac-addr | detail | interface interface numberprotocol protocol | module number | vlan vlan ] [ begin | exclude | include | expression ]
show mac-address-table dynamic [ address mac-addr | interface interface interface-number [ all | module number ] | module num | vlan vlan-id [ all | module number ] ]
address mac -address |
(Optional) Specifies a 48-bit MAC address; valid format is H.H.H. |
detail |
(Optional) Specifies a detailed display of MAC address table information. |
interface type number |
(Optional) Specifies an interface to match; valid type values are FastEthernet and GigabitEthernet, valid number values are from 1 to 9. |
interface type |
(Optional) Specifies an interface to match; valid type values are FastEthernet and GigabitEthernet. |
slot |
(Optional) Adds dynamic addresses to module in slot 1 or 2. |
port |
(Optional) Port interface number ranges based on type of Ethernet switch network module used: |
protocol protocol |
(Optional) Specifies a protocol. See the “Usage Guidelines” section for keyword definitions. |
module number |
(Optional) Displays information about the MAC address table for a specific Distributed Forwarding Card (DFC) module. |
vlan vlan |
(Optional) Displays entries for a specific VLAN; valid values are from 1 to 1005. |
begin |
(Optional) Specifies that the output display begin with the line that matches the expression. |
exclude |
(Optional) Specifies that the output display exclude lines that match the expression. |
include |
(Optional) Specifies that the output display include lines that match the specified expression. |
expression |
Expression in the output to use as a reference point. |
all |
(Optional) Specifies that the output display all dynamic MAC-address table entries. |
Privileged EXEC (#)
Release |
Modification |
---|---|
12.0(7)XE |
This command was introduced on Catalyst 6000 series switches. |
12.2(2)XT |
This command was implemented on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers. |
12.2(8)T |
This command was integrated into Cisco IOS Release 12.2(8)T on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers. |
12.2(11)T |
This command was integrated into Cisco IOS Release 12.2(11)T. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
12.2(14)SX |
Support for this command was introduced on the Catalyst 6500 series switch. |
12.2(33)SXH |
This command was changed to support the all keyword on the Catalyst 6500 series switch. |
Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers
The showmac-address-tabledynamic command output for an EtherChannel interface changes the port-number designation (for example, 5/7) to a port-group number.
Catalyst Switches
The keyword definitions for the protocol argument are:
ip --Specifies IP protocol
ipx --Specifies Internetwork Packet Exchange (IPX) protocols
assigned --Specifies assigned protocol entries
other --Specifies other protocol entries
The showmac-address-tabledynamic command output for an EtherChannel interface changes the port-number designation (for example, 5/7) to a port-group number.
Catalyst 6500 Series Switches
The mac-addressis a 48-bit MAC address and the valid format is H.H.H.
The optional modulenum keyword and argument are supported only on DFC modules. The modulenumkeyword and argument designate the module number.
The following examples show how to display all dynamic MAC address entries. The fields shown in the various displays are self-explanatory.
Router# show mac-address-table dynamic Non-static Address Table: Destination Address Address Type VLAN Destination Port ------------------- ------------ ---- -------------------- 000a.000a.000a Dynamic 1 FastEthernet4/0 002a.2021.4567 Dynamic 2 FastEthernet4/0
Router# show mac-address-table dynamic vlan mac address type protocol qos ports -----+---------------+--------+---------+---+-------------------------------- 200 0010.0d40.37ff dynamic ip -- 5/8 1 0060.704c.73ff dynamic ip -- 5/9 4095 0000.0000.0000 dynamic ip -- 15/1 1 0060.704c.73fb dynamic other -- 5/9 1 0080.1c93.8040 dynamic ip -- 5/9 4092 0050.f0ac.3058 dynamic ip -- 15/1 1 00e0.4fac.b3ff dynamic other -- 5/9
The following example shows how to display dynamic MAC address entries with a specific protocol type (in this case, assigned).
Router# show mac-address-table dynamic protocol assigned vlan mac address type protocol qos ports -----+---------------+--------+---------+---+-------------------------------- 4092 0000.0000.0000 dynamic assigned -- Router 4092 0050.f0ac.3059 dynamic assigned -- Router 1 0010.7b3b.0978 dynamic assigned -- Fa5/9 Router#
The following example shows the detailed output for the previous example.
Router# show mac-address-table dynamic protocol assigned detail MAC Table shown in details ======================================== Type Always Learn Trap Modified Notify Capture Protocol Flood -------+------------+----+--------+------+-------+--------+-----+ QoS bit L3 Spare Mac Address Age Byte Pvlan Xtag SWbits Index -----------------+--------+--------------+--------+-----+----+------+----- DYNAMIC NO NO YES NO NO assigned NO Bit Not On 0 0000.0000.0000 255 4092 0 0 0x3 DYNAMIC NO NO YES NO NO assigned NO Bit Not On 0 0050.f0ac.3059 254 4092 0 0 0x3 DYNAMIC NO NO YES NO NO assigned NO Bit Not On 0 0010.7b3b.0978 254 1 0 0 0x108 Router#
This example shows how to display all the dynamic MAC-address entries for a specific VLAN.
Router# show mac-address-table dynamic vlan 200 all Legend: * - primary entry age - seconds since last seen n/a - not aevailable vlan mac address type learn age ports ------+----------------+--------+-----+----------+-------------------------- 200 0010.0d40.37ff dynamic NO 23 Gi5/8 Router#
This example shows how to display all the dynamic MAC-address entries.
Router# show mac-address-table dynamic Legend: * - primary entry age - seconds since last seen n/a - not applicable vlan mac address type learn age ports ------+----------------+--------+-----+----------+-------------------------- * 10 0010.0000.0000 dynamic Yes n/a Gi4/1 * 3 0010.0000.0000 dynamic Yes 0 Gi4/2 * 1 0002.fcbc.ac64 dynamic Yes 265 Gi8/1 * 1 0009.12e9.adc0 static No - Router Router#
Command |
Description |
---|---|
show mac -address-tableaddress |
Displays MAC address table information for a specific MAC address. |
show mac -address-tableaging-time |
Displays the MAC address aging time. |
show mac -address-tablecount |
Displays the number of entries currently in the MAC address table. |
show mac -address-tabledetail |
Displays detailed MAC address table information. |
show mac -address-tableinterface |
Displays the MAC address table information for a specific interface. |
show mac -address-tablemulticast |
Displays multicast MAC address table information. |
show mac -address-tableprotocol |
Displays MAC address table information based on protocol. |
show mac -address-tablestatic |
Displays static MAC address table entries only. |
show mac -address-tablevlan |
Displays the MAC address table information for a specific VLAN. |
To display port-channel information, use the show pagp command in user EXEC or privileged EXEC mode.
show pagp [group-number] { counters | internal | neighbor | pgroup }
group-number |
(Optional) Channel-group number; valid values are a maximum of 64 values from 1 to 282. |
counters |
Displays the traffic information. |
internal |
Displays the internal information. |
neighbor |
Displays the neighbor information. |
pgroup |
Displays the active port channels. |
This command has no default settings.
User EXEC Privileged EXEC
Release |
Modification |
---|---|
12.2(14)SX |
Support for this command was introduced on the Supervisor Engine 720. |
12.2(17d)SXB |
Support for this command on the Supervisor Engine 2 was extended to Release 12.2(17d)SXB. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
You can enter any show pagp command to display the active port-channel information. To display the nonactive information, enter the show pagp command with a group.
The port-channel numbervalues from 257 to 282 are supported on the CSM and the FWSM only.
This example shows how to display information about the PAgP counters:
Router# show pagp counters Information Flush Port Sent Recv Sent Recv -------------------------------------- Channel group: 1 Fa5/4 2660 2452 0 0 Fa5/5 2676 2453 0 0 Channel group: 2 Fa5/6 289 261 0 0 Fa5/7 290 261 0 0 Channel group: 1023 Fa5/9 0 0 0 0 Channel group: 1024 Fa5/8 0 0 0 0 Router#
This example shows how to display internal PAgP information:
Router# show pagp 1 internal Flags: S - Device is sending Slow hello. C - Device is in Consistent state. A - Device is in Auto mode. Timers: H - Hello timer is running. Q - Quit timer is running. S - Switching timer is running. I - Interface timer is running. Channel group 1 Hello Partner PAgP Learning Port Flags State Timers Interval Count Priority Method Fa5/4 SC U6/S7 30s 1 128 Any Fa5/5 SC U6/S7 30s 1 128 Any Router#
This example shows how to display PAgP-neighbor information for all neighbors:
Router# show pagp neighbor Flags: S - Device is sending Slow hello. C - Device is in Consistent state. A - Device is in Auto mode. P - Device learns on physical port. Channel group 1 neighbors Partner Partner Partner Partner Group Port Name Device ID Port Age Flags Cap. Fa5/4 JAB031301 0050.0f10.230c 2/45 2s SAC 2D Fa5/5 JAB031301 0050.0f10.230c 2/46 27s SAC 2D Channel group 2 neighbors Partner Partner Partner Partner Group Port Name Device ID Port Age Flags Cap. Fa5/6 JAB031301 0050.0f10.230c 2/47 10s SAC 2F Fa5/7 JAB031301 0050.0f10.230c 2/48 11s SAC 2F Channel group 1023 neighbors Partner Partner Partner Partner Group Port Name Device ID Port Age Flags Cap. Channel group 1024 neighbors Partner Partner Partner Partner Group Port Name Device ID Port Age Flags Cap. Router#
Command |
Description |
---|---|
pagp learn-method |
Learns the input interface of the incoming packets. |
pagp port-priority |
Selects a port in hot standby mode. |
To display the power status for a specified port or for all ports, use the show power inline command in privileged EXEC mode.
show power inline [ interface-type slot/port ] [ actual | configured ]
interface -type |
(Optional) Type of interface. |
slot |
(Optional) Slot number. |
/ port |
(Optional) Port number. |
actual |
(Optional) Displays the present power status, which might not be the same as the configured power. |
configured |
(Optional) Displays the configured power status. |
Privileged EXEC
Release |
Modification |
---|---|
12.0(5)XU |
This command was introduced. |
12.2(2)XT |
This command was introduced on the Cisco 2600 series, the Cisco 3600 series, and the Cisco 3700 series routers to support switchport creation. |
12.2(8)T |
This command was integrated into Cisco IOS Release 12.2(8)T to support switchport creation on Cisco 2600 series, the Cisco 3600 series, and Cisco 3700 series routers. |
12.2SX |
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware. |
Cisco IOS XE 3.9S |
This command was integrated into Cisco IOS Release XE 3.9S. |
The show power inline command displays the amount of power used to operate a Cisco IP phone. To view the amount of power requested, use the show cdp neighbors command.
Use the show power inline gigabitEthernet detail command on a Cisco 4400 Series Integrated Services Router (ISR) to monitor the total available power budget on your router.
The following is sample output from the show power inlinefa0/4actual command asking for the actual status of each interface rather than what is configured for each:
Router# show power inline fastethernet 0/4 actual Interface Power -------------------- ----- FastEthernet0/4 no
Notice that the status shown for the FastEthernet interface 0/4, there is no power.
The following are sample outputs from the show power inline command and the show power inline gigabitEthernet detail commands
Router# show power inline Available:31.0(w) Used:30.8(w) Remaining:0.2(w) Interface Admin Oper Power Device Class Max (Watts) --------- ------ ---------- ------- ------------------- ----- ---- Gi0/0/0 auto on 15.4 Ieee PD 4 30.0 Gi0/0/1 auto on 15.4 Ieee PD 4 30.0 Router# show power inline gigabitEthernet 0/0/0 detail Interface: Gi0/0/0 Inline Power Mode: auto Operational status: on Device Detected: yes Device Type: Ieee PD IEEE Class: 4 Discovery mechanism used/configured: Ieee Police: off Power Allocated Admin Value: 30.0 Power drawn from the source: 15.4 Power available to the device: 15.4 Absent Counter: 0 Over Current Counter: 0 Short Current Counter: 0 Invalid Signature Counter: 0 Power Denied Counter: 0
Command |
Description |
---|---|
power inline |
Determines how inline power is applied to devices on the specified Fast Ethernet port. |
show cdp neighbors |
Displays detailed information about neighboring devices discovered using CDP. |
To issue a Simple Network Management Protocol (SNMP) trap when a MAC address violation is detected on an Ethernet hub port of a Cisco 2505, Cisco 2507, or Cisco 2516 router, use the snmptrapillegal-address command in hub configuration mode. To disable this function, use the no form of this command.
snmp trap illegal-address
no snmp trap illegal-address
This command has no arguments or keywords.
No SNMP trap is issued.
Hub configuration
Release |
Modification |
---|---|
11.1 |
This command was introduced. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
12.2SX |
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware. |
In addition to setting the snmptrapillegal-addresscommand on the Ethernet hub, you can set the frequency that the trap is sent to the network management station (NMS). This is done on the NMS via the Cisco Repeater MIB. The frequency of the trap can be configured for once only or at a decaying rate (the default). If the decaying rate is used, the first trap is sent immediately, the second trap is sent after one minute, the third trap is sent after two minutes, and so on until 32 minutes, at which time the trap is sent every 32 minutes. If you use a decaying rate, you can also set the trap acknowledgment so that the trap will be acknowledged after it is received and will no longer be sent to the network management station.
Because traps are not reliable, additional information on a port basis is provided by the Cisco Repeater MIB. The network management function can query the following information: the last illegal MAC source address, the illegal address trap acknowledgment, the illegal address trap enabled, the illegal address first heard (timestamp), the illegal address last heard (timestamp), the last illegal address trap count for the port, and the illegal address trap total count for the port.
In addition to issuing a trap when a MAC address violation is detected, the port is also disabled as long as the MAC address is invalid. The port is enabled and the trap is no longer sent when the MAC address is valid (that is, either the address was configured correctly or learned).
The following example enables an SNMP trap to be issued when a MAC address violation is detected on hub ports 2, 3, or 4. SNMP support must already be configured on the router.
Router(config)# hub ethernet 0 2 4 Router(config-hub)# snmp trap illegal-address
Command |
Description |
---|---|
hub |
Enables and configures a port on an Ethernet hub of a Cisco 2505 or Cisco 2507 router. |
To configure the speed for a Fast Ethernet or Gigabit Ethernet interface, use the speed command in interface configuration mode. To return to the default configuration, use the no form of this command.
speed { 10 | 100 | 1000 [ negotiate] | auto [ speed-list] }
no speed
10 |
Configures the interface to transmit at 10 Mbps. |
100 |
Configures the interface to transmit at 100 Mbps. |
1000 |
Configures the interface to transmit at 1000 Mbps. This keyword is valid only for interfaces that support Gigabit Ethernet. |
auto |
Enables Fast Ethernet autonegotiation. The interface automatically operates at 10 Mbps or 100 Mbps depending on environmental factors, such as the type of media and transmission speeds for the peer routers, hubs, and switches used in the network configuration. Autonegotiation is the default. |
negotiate |
(Optional) Enables or disables the link-negotiation protocol on Gigabit Ethernet ports. |
speed-list |
(Optional) Speed autonegotiation capability for a specific speed; see the “Usage Guidelines” section for valid values. |
Autonegotiation is enabled. The command is set to auto.
Interface configuration (config-if)
Release |
Modification |
---|---|
11.2(10)P |
This command was introduced. |
12.1(7)E |
This command was modified. The 1000 keyword was added for Gigabit Ethernet interfaces. |
12.2S |
This command was integrated into Cisco IOS Release 12.2 S. |
12.2(20)S2 |
This command was implemented on the 4-port 10/100 Fast Ethernet SPA and the 2-port 10/100/1000 Gigabit Ethernet SPA on the Cisco 7304 router. |
12.2(14)SX |
This command was implemented on the Supervisor Engine 720. |
12.2(17a)SX |
This command was modified. The speed-list argument was added. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
Cisco IOS XE Release 3.9S |
This command was integrated into Cisco IOS XE Release 3.9S. |
15.2(02)SA |
This command was implemented on the Cisco ME 2600X Series Ethernet Access Switches. |
Use the speed {10 | 100} command for 10/100 ports, the speed auto 10 100 1000 command for 10/100/1000 ports, and the speed 1000 [negotiate] command for Gigabit Ethernet ports.
Cisco Cloud Services Router 1000V Series
Cisco Cloud Services Router 1000V Series does not support the speed command.
Cisco 7600 Series Routers
Cisco 7600 Series Routers cannot automatically negotiate interface speed and duplex mode if either of the connecting interfaces is configured to a value other than auto.
Ethernet Interfaces
If you set the Ethernet interface speed to auto on a 10/100-Mbps or 10/100/1000-Mbps Ethernet interface, both duplex operation and speed are autonegotiated.
Gigabit Ethernet Interfaces
The Gigabit Ethernet interfaces are full duplex only. You cannot change the duplex mode on Gigabit Ethernet interfaces or on a 10/100/1000-Mbps interface that is configured for Gigabit Ethernet.
SPA Interfaces
The speed command applies to Shared Port Adapter (SPA) interfaces that use RJ-45 media. Gigabit Ethernet interfaces using fiber media support 1000-Mbps speed only and use the negotiation command to enable and disable autonegotiation.
See also “Flow Control” in the “Usage Guidelines” section.
Speed Command Syntax Combinations
The table below lists the supported command options by interface.
Interface Type |
Supported Syntax |
Default Settings |
Usage Guidelines |
---|---|---|---|
10/100-Mbps module |
speed {10 | 100} speed auto 10 100 |
auto |
If the speed is set to auto, you cannot set duplex. If the speed is set to 10 or 100, without configuring the duplex setting, the duplex is set to half by default. |
10/100/1000-Mbps interface |
speed auto 10 100 1000 |
auto |
If the speed is set to auto, you cannot set duplex. If the speed is set to 10 or 100, without configuring the duplex setting, the duplex is set to half by default. If the speed is set to 10 or 100, the interface is not forced to half duplex by default. |
100-Mbps fiber modules |
Factory set |
Not applicable. |
|
Gigabit Ethernet module |
speed 1000 [negotiate] |
Speed is 1000 or negotiation is enabled. |
Speed, duplex, flow control, and clocking negotiations are enabled. |
10-Mbps ports |
Factory set |
Not applicable. |
|
Autonegotiation
To enable the autonegotiation capability on an RJ-45 interface, you must set either the speed command or the duplex command to auto. The default configuration is that both commands are set to auto.
If you need to force an interface port to operate with certain settings and, therefore, disable autonegotiation, you must be sure that the remote link is configured for compatible link settings for proper transmission including support of flow control on the link.
When you enable link negotiation, the speed, duplex, flow control, and clocking negotiations between two Gigabit Ethernet ports are automatically enabled.
Flow Control
Flow control support is always advertised when autonegotiation is enabled.
Every interface on a 4-port 10/100 Fast Ethernet SPA supports transmission of pause frames to stop packet flow when the Modular Services Card (MSC) is full. You cannot disable flow control for an interface on the 4-port 10/100 Fast Ethernet SPA. Therefore, flow control support is not configurable, but it is advertised during autonegotiation.
If you disable autonegotiation, then you must be sure that the remote device is configured to support flow control because flow control is automatically enabled for all interfaces on the 4-port 10/100 Fast Ethernet SPA.
Speed Settings
Separate the speed-list entries with a space.
When manually configuring the interface speed to either 10 or 100 Mbps, the switch prompts you to configure duplex mode on the interface.
The following speed-list configurations are supported:
speed auto—Negotiate all speeds.
speed auto 10 100—Negotiate 10 and 100 speeds only.
speed auto 10 100 1000—Negotiate all speeds.
Speed and Duplex Combinations
The table below describes the interface behavior for various combinations of the duplex and speed command settings. The specified duplex command configured with the specified speed command produces the resulting system action.
If you decide to configure the interface speed and duplex commands manually, and enter a value other than speed auto (for example, 10 or 100 Mbps), ensure that you configure a connected interface with a matching speed using the speed command without using the auto keyword.
If you specify both a duplex and speed setting other than auto on an RJ-45 interface, then autonegotiation is disabled for the interface.
You cannot set the duplex mode to half when the port speed is set to 1000, and similarly, you cannot set the port speed to 1000 when the mode is set to half duplex. In addition, if the port speed is set to auto, the duplex command is rejected.
Caution | Changing the interface speed and duplex mode might shut down and reenable the interface during reconfiguration. |
duplex Command |
speed Command |
Resulting System Action |
---|---|---|
duplex auto |
speed auto |
Autonegotiates both speed and duplex settings. The interface advertises the capability for the following link settings: |
duplex auto |
speed 10 or speed 100 or speed 1000 |
Autonegotiates the duplex mode. The interface advertises the capability for both half-duplex and full-duplex modes at the configured speed. For example, if the speed 100 command is configured with duplex auto, then the interface advertises the following capability: |
duplex half or duplex full |
speed auto |
Autonegotiates the speed. The interface advertises the capability for duplex mode for Fast Ethernet interfaces at a speed of 10-Mbps and 100-Mbps, and Gigabit interfaces at 10-Mbps, 100-Mbps, and 1000-Mbps. For example, if the duplex full command is configured with the speed auto command, then the interface advertises the following capability: |
duplex half |
speed 10 |
Forces a speed of 10-Mbps and the half-duplex operation, and disables autonegotiation on the interface. |
duplex full |
speed 10 |
Forces a speed of10-Mbps and the full-duplex operation, and disables autonegotiation on the interface. |
duplex half |
speed 100 |
Forces a speed of 100-Mbps and the half-duplex operation, and disables autonegotiation on the interface. |
duplex full |
speed 100 |
Forces a speed of 100-Mbps and the full-duplex operation, and disables autonegotiation on the interface. |
duplex half |
speed 1000 |
Forces a speed of 1000-Mbps and the half-duplex operation, and disables autonegotiation on the interface (Gigabit Ethernet only). |
duplex full |
speed 1000 |
Forces a speed of 1000-Mbps and the full-duplex operation, and disables autonegotiation on the interface (Gigabit Ethernet only). |
The following example specifies the advertisement of only the 10 Mbps operation and either the full-duplex or half-duplex capability during autonegotiation for the second interface (port 1) on the SPA located in the bottom subslot (1) of the MSC that is installed in slot 2 of the Cisco 7304 router:
Device# configure terminal Device(config)# interface fastethernet 2/1/1 Device(config-if)# speed 10 Device(config-if)# duplex auto
With this configuration, the interface advertises the following capabilities during autonegotiation:
Command |
Description |
---|---|
duplex |
Configures the duplex operation on an interface. |
interface fastethernet |
Selects a particular Fast Ethernet interface for configuration. |
interface gigabitethernet |
Selects a particular Gigabit Ethernet interface for configuration. |
show controllers fastethernet |
Displays Fast Ethernet interface information, transmission statistics and errors, and the applicable MAC destination address and VLAN filtering tables. |
show controllers gigabitethernet |
Displays Gigabit Ethernet interface information, transmission statistics and errors, and the applicable MAC destination address and VLAN filtering tables. |
show interfaces fastethernet |
Displays information about the Fast Ethernet interfaces. |
show interfaces gigabitethernet |
Displays information about the Gigabit Ethernet interfaces. |
To put an interface that is in Layer 3 mode into Layer 2 mode for Layer 2 configuration, use the switchport command in interface configuration mode. To put an interface into Layer 3 mode, use the no form of this command.
switchport
no switchport
To modify the switching characteristics of the Layer 2-switched interface, use the switchport command (without keywords). Use the no form of this command (without keywords) to return the interface to the routed-interface status and cause all further Layer 2 configuration to be erased. Use the switchport commands (with keywords) to configure the switching characteristics.
switchport
switchport { host | nonegotiate }
no switchport
no switchport nonegotiate
To configure the server module to communicate with the router over a high-speed Multi Gigabit Fabric (MGF) backplane switch port, use the switchport command (with keywords) in interface configuration mode.
switchport { access | mode | trunk }
This command has no arguments or keywords.
host |
Optimizes the port configuration for a host connection. |
nonegotiate |
Specifies that the device will not engage in negotiation protocol on this interface. |
access |
Sets the access mode characteristics of the interface. |
mode |
Sets the interface type: Access or Trunk. |
trunk |
Sets trunk characteristics when the interface is in Trunk mode. This is the default mode. |
All interfaces are in Layer 2 mode.
Catalyst 6500/6000 Series Switches and 7600 Series Routers
The default access VLAN and trunk-interface native VLAN are default VLANs that correspond to the platform or interface hardware.
Interface configuration (config-if)
Release |
Modification |
---|---|
12.1(4)EA1 |
This command was introduced. |
12.2(14)SX |
Support for this command was introduced on the Supervisor Engine 720. |
12.2(15)ZJ |
This command was implemented on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers. |
12.2(17d)SXB |
Support for this command on the Supervisor Engine 2 was extended to Cisco IOS Release 12.2(17d)SXB. |
12.3(4)T |
This command was integrated into Cisco IOS Release 12.3(4)T on the following platforms: Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers. |
15.1(2)T |
Support for IPv6 was added. |
Cisco IOS XE Release 3.9S |
This command was implemented on Cisco UCS E-Series Servers installed in the Cisco 4400 Series Integrated Services Routers (ISR). |
Cisco 3550, 4000, and 4500 Series Switches
Use the no switchport command to put the interface into the routed-interface status and to erase all Layer 2 configurations. You must use this command before assigning an IP address to a routed port. Entering the no switchport command shuts down the port and then reenables it, which might generate messages on the device to which the port is connected.
You can verify the switchport status of an interface by entering the show running-config privileged EXEC command.
Cisco Catalyst 6500/6000 Series Switches and Cisco 7600 Series Routers
You must enter the switchport command without any keywords to configure the LAN interface as a Layer 2 interface before you can enter additional switchport commands with keywords. This action is required only if you have not entered the switchport command for the interface.
Entering the no switchport command shuts down the port and then reenables it. This action may generate messages on the device to which the port is connected.
To optimize the port configuration, entering the switchport host command sets the switch port mode to access, enables spanning tree PortFast, and disables channel grouping. Only an end station can accept this configuration.
Because spanning-tree PortFast is enabled, you should enter the switchport host command only on ports that are connected to a single host. Connecting other Cisco 7600 series routers, hubs, concentrators, switches, and bridges to a fast-start port can cause temporary spanning-tree loops.
Enable the switchport host command to decrease the time that it takes to start up packet forwarding.
The no form of the switchport nonegotiate command removes nonegotiate status.
When using the nonegotiate keyword, Dynamic Inter-Switch Link Protocol and Dynamic Trunking Protocol (DISL/DTP)-negotiation packets are not sent on the interface. The device trunks or does not trunk according to the mode parameter given: access or trunk. This command returns an error if you attempt to execute it in dynamic (auto or desirable) mode.
You must force a port to trunk before you can configure it as a SPAN-destination port. Use the switchport nonegotiate command to force the port to trunk.
The following example shows how to cause an interface to cease operating as a Layer 2 port and become a Cisco-routed (Layer 3) port:
Router(config-if)# no switchport
The following example shows how to cause the port interface to stop operating as a Cisco-routed port and convert to a Layer 2-switched interface:
Router(config-if)# switchport Router(config-if)#
Note | The switchport command is not used on platforms that do not support Cisco-routed ports. All physical ports on such platforms are assumed to be Layer 2-switched interfaces. |
The following example shows how to optimize the port configuration for a host connection:
Router(config-if)# switchport host switchport mode will be set to access spanning-tree portfast will be enabled channel group will be disabled Router(config-if)#
This example shows how to cause a port interface that has already been configured as a switched interface to refrain from negotiating trunking mode and act as a trunk or access port (depending on the mode set):
Router(config-if)# switchport nonegotiate Router(config-if)#
The following example shows how to cause an interface to cease operating as a Cisco-routed port and to convert it into a Layer 2 switched interface:
Router(config-if)# switchport
Note | The switchport command is not used on platforms that do not support Cisco-routed (Layer 3) ports. All physical ports on such platforms are assumed to be Layer 2 switched interfaces. |
The following example shows how to set the interface to access mode:
Router#configure terminal Router(config)# interface ucse 1/0/0 Router(config-if)# switchport mode access
The following example shows how to set the interface to trunk mode:
Router#configure terminal Router(config)# interface ucse 1/0/0 Router(config-if)# switchport mode trunk
Command |
Description |
---|---|
show interfaces switchport |
Displays the administrative and operational status of a switching (nonrouting) port, including port blocking and port protection settings. |
show running-config |
Displays the current operating configuration. |
switchport mode |
Sets the interface type: Access or Trunk |
switchport trunk |
Sets trunk characteristics when the interface is in Trunk mode. |
switchport access vlan |
Sets the VLAN when the interface is in Access mode. |
To set the VLAN when the interface is in access mode, use the switchport access vlan command in interface configuration or template configuration mode. To reset the access-mode VLAN to the appropriate default VLAN for the device, use the no form of this command.
switchport access vlan vlan-id
no switchport access vlan
vlan-id |
VLAN to set when the interface is in access mode; valid values are from 1 to 4094. |
The defaults are as follows:
Interface configuration (config-if)
Template configuration (config-template)
Release |
Modification |
---|---|
12.2(14)SX |
Support for this command was introduced on the Supervisor Engine 720. |
12.2(17d)SXB |
Support for this command on the Supervisor Engine 2 was extended to Release 12.2(17d)SXB. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
Cisco IOS XE Release 3.9S |
This command was implemented on Cisco UCS E-Series Servers installed in the Cisco 4400 Series Integrated Services Routers (ISR). |
Cisco IOS XE Release 3.6E |
This command was integrated into Cisco IOS XE Release 3.6E. This command is supported in template configuration mode. |
You must enter the switchport command without any keywords to configure the LAN interface as a Layer 2 interface before you can enter the switchport access vlan command. This action is required only if you have not entered the switchport command for the interface.
Entering the no switchport command shuts down the port and then reenables it. This action may generate messages on the device to which the port is connected.
The no form of the switchport access vlan command resets the access-mode VLAN to the appropriate default VLAN for the device.
The following example shows how to stop the port interface from operating as a Cisco-routed port and convert to a Layer 2 switched interface:
Device(config-if)# switchport
Note | The switchport command is not used on platforms that do not support Cisco-routed ports. All physical ports on such platforms are assumed to be Layer 2-switched interfaces. |
The following example shows how to make a port interface that has already been configured as a switched interface to operate in VLAN 2 instead of the platform’s default VLAN in interface configuration mode:
Device(config-if)# switchport access vlan 2
The following example shows how to make a port interface that has already been configured as a switched interface to operate in VLAN 2 instead of the platform’s default VLAN, using an interface template in template configuration mode:
Device# configure terminal Device(config)# template user-template1 Device(config-template)# switchport access vlan 2 Device(config-template)# end
Command |
Description |
---|---|
show interfaces switchport |
Displays the administrative and operational status of a switching (nonrouting) port. |
switchport |
Configures a LAN interface as a Layer 2 interface. |
To exclude a port from the VLAN interface link-up calculation, use the switchportautostateexcludecommand in interface configuration mode. To return to the default settings, use the no form of this command.
switchport autostate exclude
no switchport autostate exclude
This command has no keywords or arguments.
All ports are included in the VLAN interface link-up calculation.
Interface configuration
Release |
Modification |
---|---|
12.2(17b)SXA |
Support for this command was introduced on the Supervisor Engine 720. |
12.2(17d)SXB |
Support for this command was introduced on the Supervisor Engine 2. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
You must enter the switchport command without any keywords to configure the LAN interface as a Layer 2 interface before you can enter the switchportautostateexclude command. This action is required only if you have not entered the switchport command for the interface.
Note | The switchportcommand is not used on platforms that do not support Cisco-routed ports. All physical ports on such platforms are assumed to be Layer 2 switched interfaces. |
A VLAN interface configured on the MSFC is considered up if there are ports forwarding in the associated VLAN. When all ports on a VLAN are down or blocking, the VLAN interface on the MSFC is considered down. For the VLAN interface to be considered up, all the ports in the VLAN need to be up and forwarding. You can enter the switchport autostate excludecommand to exclude a port from the VLAN interface link-up calculation.
The switchport autostate exclude command marks the port to be excluded from the interface VLAN up calculation when there are multiple ports in the VLAN.
The showinterfaceinterfaceswitchport command displays the autostate mode if the mode has been set. If the mode has not been set, the autostate mode is not displayed.
This example shows how to exclude a port from the VLAN interface link-up calculation:
Router(config-if)# switchport autostate exclude
This example shows how to include a port in the VLAN interface link-up calculation:
Router(config-if)# no switchport autostate exclude
Command |
Description |
---|---|
show interfaces switchport |
Displays the administrative and operational status of a switching (nonrouting) port. |
switchport |
Configures a LAN interface as a Layer 2 interface. |
To configure an interface as a Flexlink backup interface, use the switchport backup command in interface configuration mode. To disable this configuration, use the no form of this command.
switchport backup interface type number [ preemption { delay delay | mode { bandwidth | forced | off } } ]
no switchport backup [ interface type number [ preemption { delay | mode } ] ]
interface type number |
Specifies the interface type and the module and port number to be configured as a Flexlink backup interface. |
preemption delay delay |
Specifies the preemption delay in seconds. The range is from 0 to 300 seconds. |
preemption mode bandwidth |
Specifies that a higher bandwidth interface is preferred for preemption. |
preemption mode forced |
Specifies that an active interface is preferred for preemption. |
preemption mode off |
Specifies that preemption is turned off. |
Interfaces are not configured as Flexilink backup interfaces.
Interface configuration (config-if)
Release |
Modification |
---|---|
12.2(18)SXF |
This command was introduced on the Supervisor Engine 720. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
15.1(1)SY |
This command was modified. The no form was modified so that specific backup configurations can be disabled. |
When you enable Flexlink, both the active and standby links are up physically, and mutual backup is provided.
Flexlink is supported on Layer 2 interfaces only and does not support routed ports.
The number arguement designates the module and port number. Valid values depend on the chassis and module that are used. For example, if you have a 48-port 10/100BASE-T Ethernet module that is installed in a 13-slot chassis, valid values for the slot number are from 1 to 13, and valid values for the port number are from 1 to 48.
Flexlink is designed for simple access topologies (two uplinks from a leaf node). You must ensure that there are no loops from the wiring closet to the distribution/core network to enable Flexlink to perform correctly.
Flexlink converges faster for directly connected link failures. Flexlink fast convergence does not impact any other type of network failure.
You must enter the switchport command without any keywords to configure a LAN interface as a Layer 2 interface before you can enter the switchport backup command.
You can remove all Flexilink configurations on an interface by using the no switchport backup command. You can remove specific backup configurations by using the optional keywords in the no form of this command.
Note | The switchport command is used only on platforms that support Cisco-routed ports. All physical ports on such platforms are assumed to be Layer 2 switched interfaces. |
The following example shows how to enable Flexlink on an interface. This example also shows how to configure a preemption delay of 100 seconds on an interface.
Device(config)# interface GigabitEthernet1/1 Device(config-if)# switchport Device(config-if)# switchport backup interface GigabitEthernet1/2 Device(config-if)# switchport backup interface GigabitEthernet1/2 preemption delay 100 Device(config-if)# end Device# show running interface GigabitEthernet1/1 Building configuration... Current configuration : 219 bytes ! interface GigabitEthernet1/1 switchport switchport backup interface Gi1/2 switchport backup interface Gi1/2 preemption delay 100 end Device# show interfaces switchport backup Switch Backup Interface Pairs: Active Interface Backup Interface State ------------------------------------------------------------------------ Gi1/1 Gi1/2 Active Up/Backup Down
The following example shows how to disable specific backup configurations on an interface:
Device(config)# interface GigabitEthernet1/1 Device(config-if)# no switchport backup interface GigabitEthernet1/2 preemption delay Device(config-if)# end Device# show running-config interface GigabitEthernet1/1 Building configuration... Current configuration : 219 bytes ! interface GigabitEthernet1/1 switchport switchport backup interface Gi1/2 end
The following example shows how to disable Flexlink and remove all Flexlink configurations on an interface:
Device(config)# interface GigabitEthernet1/1 Device(config-if)# no switchport backup interface GigabitEthernet1/2 Device(config-if)# end Device# show running-config interface GigabitEthernet1/1 Building configuration... Current configuration : 219 bytes ! interface GigabitEthernet1/1 switchport end
Command |
Description |
---|---|
show interfaces switchport backup |
Displays Flexlink pairs. |
show running-config |
Displays the contents of the current running configuration file or the configuration for a specific module, Layer 2 VLAN, class map, interface, map class, policy map, or VC class. |
switchport |
Configures a LAN interface as a Layer 2 interface. |
switchport autostate exclude |
Excludes a port from the VLAN interface link-up calculation. |
To prevent the unknown unicast packets from being forwarded, use the switchportblockunicastcommand in interface configuration mode. To allow the unknown unicast packets to be forwarded, use the no form of this command.
switchport block unicast
no switchport block unicast
This command has no arguments or keywords.
The default settings are as follows:
Interface configuration
Release |
Modification |
---|---|
12.2(18)SXE |
Support for this command was introduced on the Supervisor Engine 720. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
You can block the unknown unicast traffic on the switch ports.
Blocking the unknown unicast traffic is not automatically enabled on the switch ports; you must explicitly configure it.
Note | For more information about blocking the packets, refer to the Cisco 7600 Series Router Cisco IOS Software Configuration Guide. |
You can verify your setting by entering the showinterfaces interface-idswitchport command.
This example shows how to block the unknown unicast traffic on an interface:
Router(config-if)# switchport block unicast
Command |
Description |
---|---|
show interfaces switchport |
Displays the administrative and operational status of a switching (nonrouting) port. |
To set the interface type, use the switchport mode command in interface configuration mode. Use the appropriate no form of this command to reset the mode to the appropriate default mode for the device.
switchport mode { access | trunk }
no switchport mode
switchport mode { access | dot1q-tunnel | dynamic { auto | desirable } | trunk }
no switchport mode
switchport mode { access | dot1q-tunnel | dynamic { auto | desirable } | private-vlan | trunk }
no switchport mode
switchport mode private-vlan { host | promiscuous }
no switchport mode private-vlan
switchport mode { access | trunk }
no switchport mode { access | trunk }
access |
Sets a nontrunking, nontagged single VLAN Layer 2 interface. |
trunk |
Specifies a trunking VLAN Layer 2 interface. |
dot1q-tunnel |
Sets the trunking mode to TUNNEL unconditionally. |
dynamic auto |
Sets the interface to convert the link to a trunk link. |
dynamic desirable |
Sets the interface to actively attempt to convert the link to a trunk link. |
private vlan host |
Specifies that the ports with a valid private VLAN (PVLAN) association become active host private VLAN ports. |
private vlan promiscuous |
Specifies that the ports with a valid PVLAN mapping become active promiscuous ports. |
access |
Sets a nontrunking, nontagged single VLAN Layer 2 interface. |
trunk |
Specifies a trunking VLAN Layer 2 interface. |
The default is access mode.
The default mode is dependent on the platform; it should be either dynamic auto for platforms that are intended as wiring closets or dynamic desirable for platforms that are intended as backbone switches. The default for PVLAN ports is that no mode is set.
The defaults are as follows:
Interface configuration (config-if)
Release |
Modification |
---|---|
12.0(7)XE |
This command was introduced on the Cisco Catalyst 6000 family switches. |
12.1(1)E |
This command was integrated on the Cisco Catalyst 6000 family switches. |
12.1(8a)EX |
The switchport mode private-vlan {host | promiscuous} syntax was added. |
12.2(2)XT |
Creation of switchports became available on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers. |
12.2(8)T |
This command was integrated into Cisco IOS Release 12.2(8)T for creation of switchports on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers. |
12.2(14)SX |
Support for this command was introduced on the Supervisor Engine 720. |
12.2(17d)SXB |
Support for this command on the Supervisor Engine 2 was extended to Cisco IOS Release 12.2(17d)SXB. |
Cisco IOS XE Release 3.9S |
This command was implemented on Cisco UCS E-Series Servers installed in the Cisco 4400 Series Integrated Services Routers (ISR). |
Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers
If you enter a forced mode, the interface does not negotiate the link to the neighboring interface. Ensure that the interface ends match.
The no form of the command is not supported on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
Cisco Catalyst 6500/6000 Switches and Cisco 7600 Series Routers
If you enter access mode, the interface goes into permanent nontrunking mode and negotiates to convert the link into a nontrunk link even if the neighboring interface does not agree to the change.
If you enter trunk mode, the interface goes into permanent trunking mode and negotiates to convert the link into a trunk link even if the neighboring interface does not agree to the change.
If you enter dynamic auto mode, the interface converts the link to a trunk link if the neighboring interface is set to trunk or desirable mode.
If you enter dynamic desirable mode, the interface becomes a trunk interface if the neighboring interface is set to trunk, desirable, or auto mode.
If you configure a port as a promiscuous or host-PVLAN port and one of the following applies, the port becomes inactive:
The port does not have a valid PVLAN association or mapping configured.
The port is a SPAN destination.
If you delete a private-port PVLAN association or mapping, or if you configure a private port as a SPAN destination, the deleted private-port PVLAN association or mapping or the private port that is configured as a SPAN destination becomes inactive.
If you enter dot1q-tunnel mode, PortFast Bridge Protocol Data Unit (BPDU) filtering is enabled and Cisco Discovery Protocol (CDP) is disabled on protocol-tunneled interfaces.
The following example shows how to set the interface to access mode:
Router#configure terminal Router(config)# interface fastethernet 4/1 Router(config-if)#switchport mode access
The following example shows how to set the interface to trunk mode:
Router#configure terminal Router(config)# interface fastethernet 4/1 Router(config-if)#switchport mode trunk
The following example shows how to set the interface to dynamic desirable mode:
Router#configure terminal Router(config)# interface fastethernet 4/1 Router(config-if)# switchport mode dynamic desirable
The following example shows how to set a port to PVLAN-host mode:
Router#configure terminal Router(config)# interface fastethernet 4/1 Router(config-if)# switchport mode private-vlan host
The following example shows how to set a port to PVLAN-promiscuous mode:
Router#configure terminal Router(config)# interface fastethernet 4/1 Router(config-if)# switchport mode private-vlan promiscuous
The following example shows how to configure tunneling on port 4/1 and verify the configuration:
Router#configure terminal Router(config)# interface fastethernet 4/1 Router(config-if)# switchport mode dot1q-tunnel Router(config-if)# end
The following example shows how to set the interface to access mode:
Router#configure terminal Router(config)# interface ucse 1/0/0 Router(config-if)# switchport mode access
The following example shows how to set the interface to trunk mode:
Router#configure terminal Router(config)# interface ucse 1/0/0 Router(config-if)# switchport mode trunk
Command |
Description |
---|---|
show dot1q-tunnel |
Displays a list of 802.1Q tunnel-enabled ports. |
show interfaces switchport |
Displays administrative and operational status of a switching (nonrouting) port. |
show interfaces trunk |
Displays trunk information. |
switchport |
Modifies the switching characteristics of the Layer 2-switched interface. |
switchport private vlan host association |
Defines a PVLAN association for an isolated or community port. |
switchport private vlan mapping |
Defines the PVLAN mapping for a promiscuous port. |
switchport trunk |
Sets trunk characteristics when the interface is in trunking mode. |
To enable port security on an interface, use the switchportport-security command in i nterface configuration mode . To disable port security, use the no form of this command.
switchport port-security
no switchport port-security
This command has no keywords or arguments.
D isabled
Interface configuration
Release |
Modification |
---|---|
12.2(14)SX |
Support for this command was introduced on the Supervisor Engine 720. |
12.2(17d)SXB |
Support for this command on the Supervisor Engine 2 was extended to Release 12.2(17d)SXB. |
12.2(18)SXE |
This command was changed as follows on the Supervisor Engine 720: |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
Follow these guidelines when configuring port security:
With Release 12.2(18)SXE and later releases, port security is supported on trunks.
With releases earlier than Release 12.2(18)SXE, port security is not supported on trunks.
With Release 12.2(18)SXE and later releases, port security is supported on 802.1Q tunnel ports.
With releases earlier than Release 12.2(18)SXE, port security is not supported on 802.1Q tunnel ports.
A secure port cannot be a destination port for a Switch Port Analyzer (SPAN).
A secure port cannot belong to an EtherChannel.
A secure port cannot be a trunk port.
A secure port cannot be an 802.1X port. If you try to enable 802.1X on a secure port, an error message appears, and 802.1X is not enabled. If you try to change an 802.1X-enabled port to a secure port, an error message appears, and the security settings are not changed.
This example shows how to enable port security:
Router(config-if)# switchport port-security
This example shows how to disable port security:
Command |
Description |
---|---|
show port-security |
Displays information about the port-security setting. |
To configure the port security aging , use the switchport port-security aging time command in interface configuration mode . To disable aging, use the no form of this command.
switchport port-security aging { time time | type { absolute | inactivity } }
no switchport port-security aging
time time |
Sets the duration for which all addresses are secured; valid values are from 1 to 1440 minutes. |
type |
Specifies the type of aging. |
absolute |
Specifies absolute aging; see the “Usage Guidelines” section for more information. |
inactivity |
Specifies that the timer starts to run only when there is no traffic; see the “Usage Guidelines” section for more information. |
The defaults are as follows:
Interface configuration
Release |
Modification |
---|---|
12.2(14)SX |
Support for this command was introduced on the Supervisor Engine 720. |
12.2(17d)SXB |
Support for this command on the Supervisor Engine 2 was extended to Release 12.2(17d)SXB. |
12.2(18)SXE |
This command was changed as follows on the Supervisor Engine 720: |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
Follow these guidelines when configuring port security:
With Release 12.2(18)SXE and later releases, port security is supported on trunks. With releases earlier than Release 12.2(18)SXE, port security is not supported on trunks.
With Release 12.2(18)SXE and later releases, port security is supported on 802.1Q tunnel ports. With releases earlier than Release 12.2(18)SXE, port security is not supported on 802.1Q tunnel ports.
You can apply one of two types of aging for automatically learned addresses on a secure port:
Absolute aging times out the MAC address after the age-time has been exceeded, regardless of the traffic pattern. This default is for any secured port, and the age-time is set to 0.
Inactivity aging times out the MAC address only after the age_time of inactivity from the corresponding host has been exceeded.
This example shows how to set the aging time as 2 hours:
Router(config-if)# switchport port-security aging time 120
This example shows how to set the aging time as 2 minutes:
Router(config-if)# switchport port-security aging time 2
This example shows how to set the aging type on a port to absolute aging:
Router(config-if) switchport port-security aging type absolute
This example shows how to set the aging type on a port to inactivity aging:
Router(config-if) switchport port-security aging type inactivity
Command |
Description |
---|---|
show port-security |
Displays information about the port-security setting. |
To define a PVLAN association for an isolated or community port, use the switchportprivate-vlanhost-associationcommand in i nterface configuration mode . To remove the PVLAN mapping from the port, use the no form of this command.
switchport private-vlan host-association primary-vlan-id secondary-vlan-id
no switchport private-vlan host-association
primary-vlan-id |
Number of the primary VLAN of the PVLAN relationship; valid values are from 1 to 4094. |
secondary-vlan-id |
Number of the secondary VLAN of the private VLAN relationship; valid values are from 1 to 4094. |
No PVLAN is configured.
Interface configuration
Release |
Modification |
---|---|
12.2(14)SX |
Support for this command was introduced on the Supervisor Engine 720. |
12.2(17d)SXB |
Support for this command on the Supervisor Engine 2 was extended to t Release 12.2(17d)SXB. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
There is no run-time effect on the port unless it is in PVLAN-host mode. If the port is in PVLAN-host mode but neither of the VLANs exist, the command is allowed but the port is made inactive.
The secondary VLAN may be an isolated or community VLAN.
This example shows how to configure a port with a primary VLAN (VLAN 18) and secondary VLAN (VLAN 20):
Router(config-if)# switchport private-vlan host-association 18 20
This example shows how to remove the PVLAN association from the port:
Router(config-if)# no switchport private-vlan host-association
Command |
Description |
---|---|
show interfaces switchport |
Displays the administrative and operational status of a switching (nonrouting) port. |
switchport mode |
Displays the administrative and operational status of a switching (nonrouting) port. |
To define the PVLAN mapping for a promiscuous port, use the switchportprivate-vlanmapping command in interface configuration mode. To clear all mappings from the primary VLAN, use the no form of this command.
{ switchport private-vlan mapping primary-vlan-id secondary-vlan-list | add secondary-vlan-list | remove secondary-vlan-list }
no switchport private-vlan mapping
primary-vlan-id |
Number of the primary VLAN of the PVLAN relationship; valid values are from 1 to 4094. |
secondary-vlan- list |
Number of the secondary VLAN of the private VLAN relationship; valid values are from 1 to 4094. |
add |
Maps the secondary VLANs to the primary VLAN. |
remove |
Clears mapping between the secondary VLANs and the primary VLAN. |
No PVLAN mappings are configured.
Interface configuration
Release |
Modification |
---|---|
12.2(14)SX |
Support for this command was introduced on the Supervisor Engine 720. |
12.2(17d)SXB |
Support for this command on the Supervisor Engine 2 was extended to Release 12.2(17d)SXB. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
There is no run-time effect on the port unless it is in PVLAN-promiscuous mode. If the port is in PVLAN-promiscuous mode but the VLANs do not exist, the command is allowed but the port is made inactive.
The secondary VLAN may be an isolated or community VLAN.
This example shows how to configure the mapping of primary VLAN 18 to secondary isolated VLAN 20 on a port:
Router(config-if)# switchport private-vlan mapping 18 20
This example shows how to add a VLAN to the mapping:
Router(config-if)# switchport private-vlan mapping 18 add 21
This example shows how to remove the PVLAN mapping from the port:
Router(config-if)# no switchport private-vlan mapping
Command |
Description |
---|---|
show interfaces private-vlan mapping |
Displays the information about the PVLAN mapping for VLAN SVIs. |
Use the switchportprotectedcommand to isolate unicast, multicast, and broadcast traffic at Layer 2 from other protected ports on the same switch in interface configuration mode. To disable protection on the port, use the no form of the command.
switchport protected
no switchport protected
This command has no arguments or keywords.
No protected port is defined. All ports are nonprotected.
Interface configuration (config-if)
Release |
Modification |
---|---|
12.1(4)EA1 |
This command was first introduced. |
12.4(15)T |
This command was implemented on the following platforms: the Cisco 1841 Integrated Services Router (ISR), Cisco 2800 series ISRs, and Cisco 3800 series ISRs. |
The switchport protection feature is local to the switch; communication between protected ports on the same switch is possible only through a Layer 3 device. To prevent communication between protected ports on different switches, you must configure the protected ports for unique VLANs on each switch and configure a trunk link between the switches.
Beginning with Cisco IOS Release 12.4(15)T, the following Cisco ISRs support port protection when an appropriate high-speed WAN interface card (HWIC) is installed:
Cisco 1841 ISR
Cisco 2800 Series ISRs, including models 2801, 2811, 2821, and 2851
Cisco 3800 Series ISRs, including models 3825 and 3845
To support port protection, the Cisco routers listed above must be equipped with one of the following HWICs:
HWIC-4ESW
HWIC-D-9ESW
Note | Only the ports attached to the HWICs can be configured with port protection. |
A protected port does not forward any unicast, multicast, or broadcast traffic to any other protected port. A protected port continues to forward unicast, multicast, and broadcast traffic to unprotected ports and vice versa.
Port monitoring does not work if both the monitor and monitored ports are protected ports.
A protected port is different from a secure port.
The following example shows how to enable a protected port on an interface:
Switch(config)# interface gigabitethernet0/3 Switch(config-if)# switchport protected
You can verify the previous command by entering theshowinterfacesswitchportprivileged EXEC command.
Command |
Description |
---|---|
show interfaces switchport |
Displays the administrative and operational status of a switching (nonrouting) port, including port blocking and port protection settings. |
switchport block |
Prevents unknown multicast or unicast traffic on the interface. |
To set the trunk characteristics when the interface is in trunking mode, use the switchport trunk command in interface configuration mode. To reset all of the trunking characteristics back to the original defaults, use the no form of this command.
switchport trunk { encapsulation dot1q | native vlan | allowed vlan }
no switchport trunk { encapsulation dot1q | native vlan | allowed vlan }
{ switchport trunk encapsulation { isl | dot1q [ ethertype value ] | negotiate } | native vlan { tag | vlan-id } | allowed vlan vlan-list | pruning vlan vlan-list }
no switchport trunk { encapsulation { isl | dot1q [ ethertype value ] | negotiate } | native vlan [tag] | allowed vlan | pruning vlan }
switchport trunk { native vlan vlan-id | allowed vlan vlan-list }
no switchport trunk { native vlan vlan-id | allowed vlan vlan-list }
encapsulation isl |
Sets the trunk encapsulation format to Inter-Switch Link (ISL). |
encapsulation dot1q |
Sets the trunk encapsulation format to 802.1Q. |
native vlan |
Sets the native VLAN for the trunk in 802.1Q trunking mode. |
allowed vlan vlan list |
Sets the list of allowed VLANs that transmit traffic from this interface in tagged format when in trunking mode. |
ethertype value |
(Optional) Sets the EtherType value; valid values are from 0x0 to 0x5EF-0xFFFF. |
encapsulation negotiate |
Specifies that if the Dynamic Inter-Switch Link (DISL) protocol and Dynamic Trunking Protocol (DTP) negotiation do not resolve the encapsulation format, ISL is the selected format. |
native vlan tag |
Enables the native VLAN tagging state on the interface. |
native vlan vlan id |
The particular native VLAN. |
pruning vlan vlan list |
Sets the list of VLANs that are enabled for VLAN Trunking Protocol (VTP) pruning when the interface is in trunking mode. See the “Usage Guidelines” section for the vlanlistargument formatting guidelines. |
native vlan vlan-id |
|
||
allowed vlan vlan-list |
Sets the list of allowed VLANs that transmit traffic from this interface in tagged format when in trunking mode.
|
The default encapsulation type is dot1q.
The default access VLAN and trunk interface native VLAN are default VLANs that correspond to the platform or interface hardware.
The default for all VLAN lists is to include all VLANs.
The encapsulation type is dependent on the platform or interface hardware.
The access VLAN and trunk interface native VLAN are default VLANs that correspond to the platform or interface hardware.
The default for all VLAN lists is to include all VLANs.
ethertype value for 802.1Q encapsulation is 0x8100.
Interface configuration (config-if)
Release |
Modification |
---|---|
12.0(7)XE |
This command was introduced on the Catalyst 6500 series switches. |
12.1(1)E |
Switchport creation on Catalyst 6500 series switches was added. |
12.2(2)XT |
This command was introduced to support switchport creation on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers. |
12.2(8)T |
This command was integrated into Cisco IOS Release 12.2(8)T to support switch port creation on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers. |
12.2(14)SX |
This command was integrated into Cisco IOS Release 12.2(14)SX to support the Supervisor Engine 720 on the Cisco 7600 series routers and Catalyst 6500 series switches. |
12.2(17a)SX |
This command was modified to include the following: |
12.2(17d)SXB |
Support for the Supervisor Engine 2 on the Cisco 7600 series routers and Catalyst 6500 series switches was added. |
12.2(18)SXD |
This command was modified to allow the switchport trunk allowed vlancommand to be entered on interfaces where the span destination port is either a trunk or an access port. |
12.2(18)SXE |
This command added a restriction that Gigabit Ethernet (GE) Optimized Layer 2 WAN ports are not supported on the Supervisor Engine 720. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
12.4(15)T |
This command was modified to extend the range of valid VLAN IDs from 1 to 4094 for specified platforms. |
12.2(33)SXH |
This command was changed as follows: |
Cisco IOS XE Release 3.9S |
This command was implemented on Cisco UCS E-Series Servers installed in the Cisco 4400 Series Integrated Services Routers (ISR). |
802.1Q Trunks
When you connect Cisco switches through an 802.1Q trunk, make sure that the native VLAN for an 802.1Q trunk is the same on both ends of the trunk link. If the native VLAN on one end of the trunk is different from the native VLAN on the other end, spanning-tree loops might result.
Disabling spanning tree on the native VLAN of an 802.1Q trunk without disabling spanning tree on every VLAN in the network can cause spanning-tree loops. Cisco recommends that you leave spanning tree enabled on the native VLAN of an 802.1Q trunk. If this is not possible, disable spanning tree on every VLAN in the network. Make sure that your network is free of physical loops before disabling spanning tree.
When you connect two Cisco switches through 802.1Q trunks, the switches exchange spanning-tree bridge protocol data units (BPDUs) on each VLAN allowed on the trunks. The BPDUs on the native VLAN of the trunk are sent untagged to the reserved IEEE 802.1d spanning-tree multicast MAC address (01-80-C2-00-00-00). The BPDUs on all other VLANs on the trunk are sent tagged to the reserved Shared Spanning Tree Protocol (SSTP) multicast MAC address (01-00-0c-cc-cc-cd).
The 802.1Q switches that are not Cisco switches maintain only a single instance of spanning-tree (Mono Spanning Tree [MST]) that defines the spanning-tree topology for all VLANs. When you connect a Cisco switch to a switch through an 802.1Q trunk without a Cisco switch, the MST of the switch and the native VLAN spanning tree of the Cisco switch combine to form a single spanning-tree topology known as the Common Spanning Tree (CST).
Because Cisco switches transmit BPDUs to the SSTP multicast MAC address on VLANs other than the native VLAN of the trunk, switches that are not Cisco switches do not recognize these frames as BPDUs and flood them on all ports in the corresponding VLAN. Other Cisco switches connected to the 802.1Q cloud receive these flooded BPDUs. This condition allows Cisco switches to maintain a per-VLAN spanning-tree topology across a cloud of 802.1Q switches that are not Cisco switches. The 802.1Q cloud of switches separating the Cisco switches is treated as a single broadcast segment among all switches connected to the 802.1Q cloud of switches that are not Cisco switches through 802.1Q trunks.
Make sure that the native VLAN is the same on all of the 802.1Q trunks that connect the Cisco switches to the 802.1Q cloud of switches that are not Cisco switches.
If you are connecting multiple Cisco switches to a 802.1Q cloud of switches that are not Cisco switches, all of the connections must be through 802.1Q trunks. You cannot connect Cisco switches to an 802.1Q cloud of switches that are not Cisco switches through ISL trunks or through access ports. Doing so will cause the switch to place the ISL trunk port or access port into the spanning-tree “port inconsistent” state and no traffic will pass through the port.
Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers
The switchport trunk encapsulation command is supported only for platforms and interface hardware that can support 802.1Q formats.
The vlanlist format is all | none | add | remove | exceptvlanlist[,vlanlist...] where:
all --Specifies all VLANs from 1 to 1005. Beginning with Cisco IOS Release 12.4(15)T, the valid VLAN ID range is from 1 to 4094.
none --Indicates an empty list. This keyword is not supported in the switchport trunk allowed vlan form of the command.
add --Adds the defined list of VLANs to those currently set instead of replacing the list.
remove --Removes the defined list of VLANs from those currently set instead of replacing the list.
except --Lists the VLANs that should be calculated by inverting the defined list of VLANs.
vlan list-- Is either a single VLAN number from 1 to 1005 or a continuous range of VLANs described by two VLAN numbers, the lesser one first, separated by a hyphen that represents the VLAN IDs of the allowed VLANs when this port is in trunking mode. Beginning with Cisco IOS Release 12.4(15)T, the valid VLAN ID range is from 1 to 4094.
Cisco 7600 Series Routers and Catalyst 6500 Series Switches
This command is not supported on GE Layer 2 WAN ports.
You can enter the switchport trunk command only on the PO. If you enter the switchport trunk command on a port member the following message is displayed:
Configuration is not allowed on Port members. Remove the interface from the Port Channel to modify its config
The switchport trunk encapsulation dot1qcommand is supported only for platforms and interface hardware that can support both ISL and 802.1Q formats. Only 802.1Q encapsulation is supported by shared port adapters (SPAs).
If you enter the switchport trunk encapsulation isl command on a port channel containing an interface that does not support ISL-trunk encapsulation, the command is rejected.
You can enter the switchport trunk allowed vlan command on interfaces where the span destination port is either a trunk or an access port.
You can enter the switchport trunk native vlan tag command to enable the tagging of native VLAN traffic on a per-port basis. When tagging is enabled, all the packets on the native VLAN are tagged and all incoming untagged data packets are dropped, but untagged control packets are accepted. When tagging is disabled, the native VLAN packets going out on trunk ports are not tagged and the incoming untagged packets are allowed and assigned to the native VLAN. The no switchport trunknative vlan tag command overrides the vlan dot1q tag native command for global tagging.
Note | The switchport trunk native vlan tag interface configuration mode command does not enable native VLAN tagging unless you first configure the switch to tag native VLAN traffic globally. To enable native VLAN tagging globally, use the vlan dot1q tag native command in global configuration mode. |
Note | The switchport trunk pruning vlan vlan-list command does not support extended-range VLANs; valid vlan-list values are from 1 to 1005. |
The dot1q ethertype value keyword and argument are not supported on port-channel interfaces. You can enter the command on the individual port interface only. Also, you can configure the ports in a channel group to have different EtherType configurations.
Caution | Be careful when configuring the custom EtherType value on a port. If you enter the negotiate keyword and DISL and Dynamic Trunking Protocol (DTP) negotiation do not resolve the encapsulation format, then ISL is the selected format and may pose as a security risk. The no form of this command resets the trunk-encapsulation format to the default. |
The no form of the switchport trunk native vlan command resets the native mode VLAN to the appropriate default VLAN for the device.
The no form of the switchport trunk native vlan tag command configures the Layer 2 port not to tag native VLAN traffic.
The no form of the switchport trunk allowed vlan command resets the list to the default list, which allows all VLANs.
The no form of the switchport trunk pruning vlancommand resets the list to the default list, which enables all VLANs for VTP pruning.
The no form of the switchport trunk encapsulation dot1qethertypevalue command resets the list to the default value.
The vlan-list format is all | none | add | remove | except [vlan-list[,vlan-list...]] where:
all --Specifies all the appropriate VLANs. This keyword is not supported in the switchporttrunkpruningvlan command.
none --Indicates an empty list. This keyword is not supported in the switchporttrunkallowedvlan command.
add vlan-list , vlan-list... ]-- Adds the defined list of VLANs to those currently set instead of replacing the list.
remove vlan-list , vlan-list... ]-- Removes the defined list of VLANs from those currently set instead of replacing the list. You can remove VLAN 1. If you remove VLAN 1 from a trunk, the trunk interface continues to send and receive management traffic (for example, Cisco Discovery Protocol, version 3; VTP; Port Aggregation Protocol, version 4 (PAgP4); and DTP) in VLAN 1.
Note | You can remove any of the default VLANs (1002 to 1005) from a trunk; this action is not allowed in earlier releases. |
except vlan-list , vlan-list... ] --Excludes the specified list of VLANs from those currently set instead of replacing the list.
vlan-list , vlan-list... -- Specifies a single VLAN number from 1 to 4094 or a continuous range of VLANs that are described by two VLAN numbers from 1 to 4094. You can specify multiple VLAN numbers or ranges of numbers using a comma-separated list.
To specify a range of VLANs, enter the smaller VLAN number first, separated by a hyphen and the larger VLAN number at the end of the range.
Do not enable the reserved VLAN range (1006 to 1024) on trunks when connecting a Cisco 7600 series router running the Cisco IOS software on both the supervisor engine and the Multilayer Switch Feature Card (MSFC) to a Cisco 7600 series router running the Catalyst operating system. These VLANs are reserved in Cisco 7600 series routers running the Catalyst operating system. If enabled, Cisco 7600 series routers running the Catalyst operating system may disable the ports if a trunking channel is between these systems.
Cisco UCS E-Series Server Installed in Cisco 4400 Integrated Services Routers
Note | To set trunk characteristics, the interface must be in trunk mode. |
all—Specifies all VLANs: 1-2349—VLAN IDs in range 1; and 2450-4095—VLAN IDs in range 2.
none—Indicates an empty list.
add—Adds the defined list of VLANs to those currently set instead of replacing the list.
remove—Removes the defined list of VLANs from those currently set instead of replacing the list.
except—Lists the VLANs that should be calculated by inverting the defined list of VLANs.
WORD—Is either a single VLAN number from 1 to 4095 or a continuous range of VLANs described by two VLAN numbers, the lesser one first, separated by a hyphen that represents the VLAN IDs of the allowed VLANs when this port is in trunking mode.
The following example shows how to cause a port interface configured as a switched interface to encapsulate in 802.1Q trunking format regardless of its default trunking format in trunking mode:
Router(config-if)# switchport trunk encapsulation dot1q
The following example shows how to configure the Layer 2 port to tag native VLAN traffic:
Router(config-if)# switchport trunk native vlan tag
Note | To set trunk characteristics, the interface must be in trunk mode. |
The following example shows how to allow trunking on specified VLANs:
Router(config)# interface ucse 1/0/0 Router(config-if)# switchport mode trunk Router(config-if)# switchport trunk allowed vlan 1-2,40,60,1002-1005
Command |
Description |
---|---|
show interfaces switchport |
Displays administrative and operational status of a switching (nonrouting) port. |
vlan dot1q tag native |
Enables dot1q tagging for all VLANs in a trunk. |
To configure a voice VLAN on a multiple-VLAN access port, use the switchportvoicevlan command in interface configuration mode. To remove the voice VLAN from the switch port, use the no form of the command.
switchport voice vlan { vlan-id | dot1p | none | untagged }
no switchport voice vlan
vlan id |
Voice VLAN identifier (VVID) of the VLAN used for voice traffic. Valid IDs are from 1 to 1005 (IDs 1006 to 4096 are not supported). Do not enter leading zeros. The switch port is an 802.1Q trunk port. |
dot1p |
The telephone uses priority tagging and uses VLAN 0. The switch port is an 802.1Q trunk port. |
none |
The telephone is not instructed through the command line interface (CLI) about the voice VLAN. The telephone uses its own configuration from the telephone keypad and transmits untagged voice traffic in the default VLAN. |
untagged |
The telephone does not tag frames; it uses VLAN 4095. The switch port can be an access port or an 802.1Q trunk port. |
The switch default is to not automatically configure the telephone (none).
The Cisco IP 7960 telephone default is to generate an 802.1Q/802.1P frame.
Interface configuration
Release |
Modification |
---|---|
12.2(2)XT |
This command was introduced. |
12.2(8)T |
This command was integrated into Cisco IOS Release 12.2(8)T to support creation of switchports . |
12.2(14)SX |
This command was integrated into Cisco IOS Release 12.2(14)SX and introduced on the Supervisor Engine 720. |
12.2(17d)SXB |
This command was integrated into Cisco IOS Release 12.2(17d)SXB and introduced on the Supervisor Engine 2. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
12.2(33)SXI |
This command was integrated into Cisco IOS Release 12.2(33)SXI. |
This command does not create a voice VLAN. You can create a voice VLAN in VLAN-configuration mode by entering the vlan(globalconfigurationmode) command. If you configure both the native VLAN and the voice VLAN in the VLAN database and set the switch port to multiple-VLAN access mode, this command brings up the switch port as operational.
If you enter a voice VLAN identifier, the switch port sends CDP packets that configure the IP phone to transmit voice traffic in the voice VLAN in 802.1Q frames that are tagged with a Layer 2 CoS value . The default Layer 2 CoS is 5. The default Layer 3 IP-precedence value is 5.
If you enter dot1p, the switch port sends CDP packets that configure the IP phone to transmit voice traffic in the default VLAN in 802.1p frames that are tagged with a Layer 2 CoS value.
If you enter none, the switch port does not send CDP packets with VVID TLVs.
If you enter untagged, the switch port is enabled to receive untagged packets only.
This example shows how to create an operational multiple-VLAN access port with VLAN 101 as the voice VLAN:
Router(config-if)# switchport Router(config-if)# switchport mode access Router(config-if)# switchport access vlan 100 Router(config-if)# switchport voice vlan 101 Router(config-if)
This example shows how to change the multiple-VLAN access port to a normal access port:
Router(config-if)# interface fastethernet5/1 Router(config-if)# no switchport voice vlan Router(config-if)
Command |
Description |
---|---|
switchport access vlan |
Sets the VLAN when the interface is in access mode. |
switchport mode |
Sets the interface type. |