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This document describes how the IEEE 802.3ad Link Bundling feature leverages the EtherChannel infrastructure within Cisco IOS XE software to manage the bundling of Ethernet links. The supported Ethernet link types for link bundling are Gigabit Ethernet and Ten Gigabit Ethernet.
Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the Feature Information Table at the end of this document.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Gigabit EtherChannel (GEC) is high-performance Ethernet technology that provides Gigabit per second (Gb/s) transmission rates. A Gigabit EtherChannel bundles individual Ethernet links (Gigabit Ethernet or Ten Gigabit Ethernet) into a single logical link that provides the aggregate bandwidth of up to four physical links. All LAN ports in each EtherChannel must be the same speed and all must be configured as either Layer 2 or Layer 3 LAN ports. Inbound broadcast and multicast packets on one link in an EtherChannel are blocked from returning on any other link in the EtherChannel.
When a link within an EtherChannel fails, traffic previously carried over the failed link switches to the remaining links within that EtherChannel. Also when a failure occurs, a trap is sent that identifies the device, the EtherChannel, and the failed link.
Each EtherChannel has a numbered port channel interface that must be manually created before interfaces can be added to the channel group. The configuration of a port channel interface affects all LAN ports assigned to that port channel interface.
To change the parameters of all ports in an EtherChannel, change the configuration of the port channel interface; for example, if you want to configure Spanning Tree Protocol or configure a Layer 2 EtherChannel as a trunk. Any configuration or attribute changes you make to the port channel interface are propagated to all interfaces within the same channel group as the port channel; that is, configuration changes are propagated to the physical interfaces that are not part of the port channel but are part of the channel group.
The configuration of a LAN port affects only that LAN port.
The IEEE 802.3ad Link Bundling feature provides a method for aggregating multiple Ethernet links into a single logical channel based on the IEEE 802.3ad standard. This feature helps improve the cost effectiveness of a device by increasing cumulative bandwidth without necessarily requiring hardware upgrades. In addition, IEEE 802.3ad Link Bundling provides a capability to dynamically provision, manage, and monitor various aggregated links and enables interoperability between various Cisco devices and devices of third-party vendors.
LACP supports the automatic creation of EtherChannels by exchanging LACP packets between LAN ports. LACP packets are exchanged only between ports in passive and active modes. The protocol "learns" the capabilities of LAN port groups dynamically and informs the other LAN ports. After LACP identifies correctly matched Ethernet links, it facilitates grouping the links into an EtherChannel. Then the EtherChannel is added to the spanning tree as a single bridge port.
Both the passive and active modes allow LACP to negotiate between LAN ports to determine if they can form an EtherChannel, based on criteria such as port speed and trunking state. (Layer 2 EtherChannels also use VLAN numbers.) LAN ports can form an EtherChannel when they are in compatible LACP modes, as in the following examples:
LACP uses the following parameters:
On ports configured to use LACP, it tries to configure the maximum number of compatible ports in an EtherChannel, up to the maximum allowed by the hardware. To use the hot standby feature in the event a channel port fails, both ends of the LACP bundle must support the lacp max-bundle command.
As a control protocol, LACP uses the Slow Protocol Multicast address of 01-80-C2-00-00-02 to transmit LACP protocol data units (PDUs). Aside from LACP, the Slow Protocol linktype is to be utilized by operations, administration, and maintenance (OAM) packets, too. Subsequently, a subtype field is defined per the IEEE 802.3ad standard [1] (Annex 43B, section 4) differentiating LACP PDUs from OAM PDUs.
Note |
LACP and Port Aggregation Control Protocol (PAgP) are not compatible. Ports configured for PAgP cannot form port channels on ports configured for LACP, and ports configured for LACP cannot form port channels on ports configured for PAgP. |
The following LACP enhancements are supported:
The LACP (802.3ad) for Gigabit Interfaces feature bundles individual Ethernet links (Gigabit Ethernet or Ten Gigabit Ethernet) into a single logical link that provides the aggregate bandwidth of up to four physical links.
All LAN ports on a port channel must be the same speed and must all be configured as either Layer 2 or Layer 3 LAN ports. If a segment within a port channel fails, traffic previously carried over the failed link switches to the remaining segments within the port channel. Inbound broadcast and multicast packets on one segment in a port channel are blocked from returning on any other segment of the port channel.
Note |
The network device to which a Cisco ASR 1000 series router is connected may impose its own limits on the number of bundled ports per port channel. |
The table below lists the features that are supported on Gigabit EtherChannel bundles on a Cisco ASR1000 series router.
Table 1 | Gigabit EtherChannel Bundle Features |
Cisco IOS XE Release |
Feature |
Bundle Interface |
---|---|---|
2.5 |
Access control lists (ACLs) per bundle |
Supported |
All Ethernet routing protocols |
Supported |
|
Intelligent Service Gateway (ISG) IP sessions |
Not Supported |
|
Interface statistics |
Supported |
|
IP switching |
Supported |
|
IPv4: unicast and multicast |
Supported |
|
IPv6: unicast without load balancing across member links |
Supported |
|
IPv6: multicast |
Not Supported |
|
Layer 2 Tunneling Protocol (L2TP), Generic Routing Encapsulation (GRE), IPinIP, Any Transport Over Multiprotocol Label Switching (MPLS) (AToM) tunnels |
Supported |
|
|
MPLS (6PE) |
Supported |
Multicast VPN |
Not Supported |
|
Policy Based Routing (PBR) |
Not Supported |
|
PPPoX (PPPoEoE, PPPoEoQinQ, PPPoVLAN) |
Not Supported |
|
VLANs |
Supported |
|
2.6 |
Virtual Private Network (VPN) VPN Routing and Forwarding (VRF) |
Supported |
Port channel interfaces that are configured improperly with LACP are disabled automatically to avoid network loops and other problems. To avoid configuration problems, observe these guidelines and restrictions:
Perform this task to enable LACP.
You must manually create a port channel logical interface. Perform this task to configure a port channel.
This example shows how to verify the configuration:
Router# show running-config interface port-channel 10
Building configuration...
Current configuration:
!
interface Port-channel10
ip address 172.31.52.10 255.255.255.0
no ip directed-broadcast
end
Perform this task to create a port channel with two bundled ports. You can configure a maximum of four bundled ports per port channel.
Router> enable Router# configure terminal Router(config)# interface port-channel 1 Router(config-if)# ip address 10.1.1.1 255.255.255.0 Router(config-if)# interface gigabitethernet 2/0/0 Router(config-if)# no ip address Router(config-if)# channel-group 1 mode active Router(config-if)# exit Router(config)# interface gigabitethernet 4/0/0 Router(config-if)# no ip address Router(config-if)# channel-group 1 mode active Router(config-if)# end
Perform this task to set the LACP system priority and port priority. The system ID is the combination of the LACP system priority and the MAC address of a device. The port identifier is the combination of the port priority and port number.
Router> enable Router# configure terminal Router(config)# lacp system-priority 200 Router(config)# interface gigabitethernet 0/1/1 Router(config-if)# lacp port-priority 500 Router(config-if)# end
This example shows how to verify the LACP configuration:
Router# show lacp 200
200.abcd.abcd.abcd.
Perform this task to add and remove an interface from a link bundle.
Perform this task to remove a Gigabit Ethernet port channel group from a physical port.
Router> enable Router# configure terminal Router(config)# no interface port-channel 1 Router(config)# end
Perform this task to set a minimum number of active links.
Perform this task to monitor LACP activity in the network.
Use the debug lacp command to display LACP configuration and activity details.
The following sample output from a debug lacp all command shows that a remote device is removing a link and also adding a link.
The following sample output shows a remote device removing a link:
Router1# debug lacp all
Link Aggregation Control Protocol all debugging is on
Router1#
*Aug 20 17:21:51.685: LACP :lacp_bugpak: Receive LACP-PDU packet via Gi5/0/0
*Aug 20 17:21:51.685: LACP : packet size: 124
*Aug 20 17:21:51.685: LACP: pdu: subtype: 1, version: 1
*Aug 20 17:21:51.685: LACP: Act: tlv:1, tlv-len:20, key:0x1, p-pri:0x8000, p:0x14, p-state:0x3C,
s-pri:0xFFFF, s-mac:0011.2026.7300
*Aug 20 17:21:51.685: LACP: Part: tlv:2, tlv-len:20, key:0x5, p-pri:0x8000, p:0x42, p-state:0x3D,
s-pri:0x8000, s-mac:0014.a93d.4a00
*Aug 20 17:21:51.685: LACP: col-tlv:3, col-tlv-len:16, col-max-d:0x8000
*Aug 20 17:21:51.685: LACP: term-tlv:0 termr-tlv-len:0
*Aug 20 17:21:51.685: LACP: Gi5/0/0 LACP packet received, processing
*Aug 20 17:21:51.685: lacp_rx Gi5: during state CURRENT, got event 5(recv_lacpdu)
*Aug 20 17:21:59.869: LACP: lacp_p(Gi5/0/0) timer stopped
*Aug 20 17:21:59.869: LACP: lacp_p(Gi5/0/0) expired
*Aug 20 17:21:59.869: lacp_ptx Gi5: during state SLOW_PERIODIC, got event 3(pt_expired)
*Aug 20 17:21:59.869: @@@ lacp_ptx Gi5: SLOW_PERIODIC -> PERIODIC_TX
*Aug 20 17:21:59.869: LACP: Gi5/0/0 lacp_action_ptx_slow_periodic_exit entered
*Aug 20 17:21:59.869: LACP: lacp_p(Gi5/0/0) timer stopped
*Aug 20 17:22:00.869: LACP: lacp_t(Gi5/0/0) timer stopped
*Aug 20 17:22:00.869: LACP: lacp_t(Gi5/0/0) expired
*Aug 20 17:22:19.089: LACP :lacp_bugpak: Receive LACP-PDU packet via Gi5/0/0
*Aug 20 17:22:19.089: LACP : packet size: 124
*Aug 20 17:22:19.089: LACP: pdu: subtype: 1, version: 1
*Aug 20 17:22:19.089: LACP: Act: tlv:1, tlv-len:20, key:0x1, p-pri:0x8000, p:0x14, p-state:0x4,
s-pri:0xFFFF, s-mac:0011.2026.7300
*Aug 20 17:22:19.089: LACP: Part: tlv:2, tlv-len:20, key:0x5, p-pri:0x8000, p:0x42, p-state:0x34,
s-pri:0x8000, s-mac:0014.a93d.4a00
*Aug 20 17:22:19.089: LACP: col-tlv:3, col-tlv-len:16, col-max-d:0x8000
*Aug 20 17:22:19.089: LACP: term-tlv:0 termr-tlv-len:0
*Aug 20 17:22:19.089: LACP: Gi5/0/0 LACP packet received, processing
*Aug 20 17:22:19.089: lacp_rx Gi5: during state CURRENT, got event 5(recv_lacpdu)
*Aug 20 17:22:19.989: LACP: lacp_t(Gi5/0/0) timer stopped
*Aug 20 17:22:19.989: LACP: lacp_t(Gi5/0/0) expired
*Aug 20 17:22:19.989: LACP: timer lacp_t(Gi5/0/0) started with interval 1000.
*Aug 20 17:22:19.989: LACP: lacp_send_lacpdu: (Gi5/0/0) About to send the 110 LACPDU
*Aug 20 17:22:19.989: LACP :lacp_bugpak: Send LACP-PDU packet via Gi5/0/0
*Aug 20 17:22:19.989: LACP : packet size: 124
*Aug 20 17:22:20.957: LACP: lacp_t(Gi5/0/0) timer stopped
*Aug 20 17:22:20.957: LACP: lacp_t(Gi5/0/0) expired
*Aug 20 17:22:21.205: %LINK-3-UPDOWN: Interface GigabitEthernet5/0/0, changed state to down
*Aug 20 17:22:21.205: LACP: lacp_hw_off: Gi5/0/0 is going down
*Aug 20 17:22:21.205: LACP: if_down: Gi5/0/0
*Aug 20 17:22:21.205: lacp_ptx Gi5: during state SLOW_PERIODIC, got event 0(no_periodic)
*Aug 20 17:22:22.089: %LINEPROTO-5-UPDOWN: Line protocol on Interface Port-channel5, changed state to down
*Aug 20 17:22:22.153: %C10K_ALARM-6-INFO: CLEAR CRITICAL GigE 5/0/0 Physical Port Link Down
*Aug 20 17:22:23.413: LACP: Gi5/0/0 oper-key: 0x0
*Aug 20 17:22:23.413: LACP: lacp_hw_on: Gi5/0/0 is coming up
*Aug 20 17:22:23.413: lacp_ptx Gi5: during state NO_PERIODIC, got event 0(no_periodic)
*Aug 20 17:22:23.413: @@@ lacp_ptx Gi5: NO_PERIODIC -> NO_PERIODIC
*Aug 20 17:22:23.413: LACP: Gi5/0/0 lacp_action_ptx_no_periodic entered
*Aug 20 17:22:23.413: LACP: lacp_p(Gi5/0/0) timer stopped
*Aug 20 17:22:24.153: %LINK-3-UPDOWN: Interface GigabitEthernet5/0/0, changed state to up
*Aug 20 17:22:24.153: LACP: lacp_hw_on: Gi5/0/0 is coming up
*Aug 20 17:22:24.153: lacp_ptx Gi5: during state FAST_PERIODIC, got event 0(no_periodic)
*Aug 20 17:22:24.153: @@@ lacp_ptx Gi5: FAST_PERIODIC -> NO_PERIODIC
*Aug 20 17:22:24.153: LACP: Gi5/0/0 lacp_action_ptx_fast_periodic_exit entered
*Aug 20 17:22:24.153: LACP: lacp_p(Gi5/0/0) timer stopped
*Aug 20 17:22:24.153: LACP:
*Aug 20 17:22:25.021: LACP: lacp_p(Gi5/0/0) timer stopped
*Aug 20 17:22:25.021: LACP: lacp_p(Gi5/0/0) expired
*Aug 20 17:22:25.021: lacp_ptx Gi5: during state FAST_PERIODIC, got event 3(pt_expired)
*Aug 20 17:22:25.021: @@@ lacp_ptx Gi5: FAST_PERIODIC -> PERIODIC_TX
*Aug 20 17:22:25.021: LACP: Gi5/0/0 lacp_action_ptx_fast_periodic_exit entered
*Aug 20 17:22:25.021: LACP: lacp_p(Gi5/0/0) timer stopped
*Aug 20 17:22:25.917: LACP: lacp_p(Gi5/0/0) timer stopped
*Aug 20 17:22:25.917: LACP: lacp_p(Gi5/0/0) expired
*Aug 20 17:22:25.917: lacp_ptx Gi5: during state FAST_PERIODIC, got event 3(pt_expired)
*Aug 20 17:22:25.917: @@@ lacp_ptx Gi5: FAST_PERIODIC -> PERIODIC_TX
*Aug 20 17:22:25.917: LACP: Gi5/0/0 lacp_action_ptx_fast_periodic_exit entered
*Aug 20 17:22:25.917: LACP: lacp_p(Gi5/0/0) timer stopped
Router1#
The following sample output shows a remote device adding a link:
Router1# *Aug 20 17:23:54.005: LACP: lacp_t(Gi5/0/0) timer stopped *Aug 20 17:23:54.005: LACP: lacp_t(Gi5/0/0) expired *Aug 20 17:23:55.789: %C10K_ALARM-6-INFO: ASSERT CRITICAL GigE 5/0/0 Physical Port Link Down *Aug 20 17:23:56.497: %C10K_ALARM-6-INFO: CLEAR CRITICAL GigE 5/0/0 Physical Port Link Down *Aug 20 17:24:19.085: LACP: lacp_p(Gi5/0/0) timer stopped *Aug 20 17:24:19.085: LACP: lacp_p(Gi5/0/0) expired *Aug 20 17:24:19.085: lacp_ptx Gi5: during state SLOW_PERIODIC, got event 3(pt_expired) *Aug 20 17:24:19.085: @@@ lacp_ptx Gi5: SLOW_PERIODIC -> PERIODIC_TX *Aug 20 17:24:19.085: LACP: Gi5/0/0 lacp_action_ptx_slow_periodic_exit entered *Aug 20 17:24:19.085: LACP: lacp_p(Gi5/0/0) timer stopped *Aug 20 17:24:19.957: LACP: lacp_t(Gi5/0/0) timer stopped *Aug 20 17:24:19.957: LACP: lacp_t(Gi5/0/0) expired *Aug 20 17:24:21.073: LACP :lacp_bugpak: Receive LACP-PDU packet via Gi5/0/0 *Aug 20 17:24:21.073: LACP : packet size: 124 *Aug 20 17:24:21.073: LACP: pdu: subtype: 1, version: 1 *Aug 20 17:24:21.073: LACP: Act: tlv:1, tlv-len:20, key:0x1, p-pri:0x8000, p:0x14, p-state:0xC, s-pri:0xFFFF, s-mac:0011.2026.7300 *Aug 20 17:24:21.073: LACP: Part: tlv:2, tlv-len:20, key:0x0, p-pri:0x8000, p:0x42, p-state:0x75, s-pri:0x8000, s-mac:0014.a93d.4a00 *Aug 20 17:24:21.073: LACP: col-tlv:3, col-tlv-len:16, col-max-d:0x8000 *Aug 20 17:24:21.073: LACP: term-tlv:0 termr-tlv-len:0 *Aug 20 17:24:21.073: LACP: Gi5/0/0 LACP packet received, processing *Aug 20 17:24:21.073: lacp_rx Gi5: during state DEFAULTED, got event 5(recv_lacpdu) *Aug 20 17:24:21.929: LACP: lacp_t(Gi5/0/0) timer stopped *Aug 20 17:24:21.929: LACP: lacp_t(Gi5/0/0) expired *Aug 20 17:24:21.929: LACP: timer lacp_t(Gi5/0/0) started with interval 1000. *Aug 20 17:24:21.929: LACP: lacp_send_lacpdu: (Gi5/0/0) About to send the 110 LACPDU *Aug 20 17:24:21.929: LACP :lacp_bugpak: Send LACP-PDU packet via Gi5/0/0 *Aug 20 17:24:21.929: LACP : packet size: 124 *Aug 20 17:24:22.805: LACP: lacp_t(Gi5/0/0) timer stopped *Aug 20 17:24:22.805: LACP: lacp_t(Gi5/0/0) expired *Aug 20 17:24:23.025: LACP: lacp_w(Gi5/0/0) timer stopped *Aug 20 17:24:23.025: LACP: lacp_w(Gi5/0/0) expired *Aug 20 17:24:23.025: lacp_mux Gi5: during state WAITING, got event 4(ready) *Aug 20 17:24:23.025: @@@ lacp_mux Gi5: WAITING -> ATTACHED *Aug 20 17:24:23.921: LACP: lacp_t(Gi5/0/0) timer stopped *Aug 20 17:24:23.921: LACP: lacp_t(Gi5/0/0) expired *Aug 20 17:24:26.025: %LINEPROTO-5-UPDOWN: Line protocol on Interface Port-channel5, changed state to up
To display Gigabit Ethernet port channel information, use the show interfaces port-channel command in user EXEC mode or privileged EXEC mode. The following example shows information about port channels configured on ports 0/2 and 0/3. The default MTU is set to 1500 bytes.
Router# show interfaces port-channel 1
Port-channel1 is up, line protocol is up
Hardware is GEChannel, address is 0013.19b3.7748 (bia 0000.0000.0000)
MTU 1500 bytes, BW 2000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
ARP type: ARPA, ARP Timeout 04:00:00
No. of active members in this channel: 2
Member 0 : GigabitEthernet3/0/0 , Full-duplex, 1000Mb/s Member 1 : GigabitEthernet7/1/0 , Full-duplex, 1000Mb/s
Last input 00:00:05, output never, output hang never
Last clearing of "show interface" counters 00:04:40
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Interface Port-channel1 queueing strategy: PXF First-In-First-Out
Output queue 0/8192, 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 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
3 packets output, 180 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 PAUSE output
0 output buffer failures, 0 output buffers swapped out
The table below describes the significant fields shown in the display.
Table 2 | show interfaces port-channel Field Descriptions |
Field |
Description |
---|---|
Port-channel1 is up, line protocol is up |
Indicates the bundle interface is currently active and can transmit and receive or it has been taken down by an administrator. |
Hardware is |
Hardware type (Gigabit 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. |
reliability |
Reliability of the interface as a fraction of 255 (255/255 is 100 percent reliability), calculated as an exponential average over 5 minutes. |
tx load rxload |
Transmit and receive 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 type assigned to the interface. |
loopback |
Indicates if loopbacks are set. |
keepalive |
Indicates if keepalives are set. |
ARP type |
Address Resolution Protocol (ARP) type on the interface. |
ARP Timeout |
Number of hours, minutes, and seconds an ARP cache entry stays in the cache. |
No. of active members in this channel |
Number of bundled ports (members) currently active and part of the port channel group. |
Member <no.> Gigabit Ethernet: <no. /no. /no. > |
Number of the bundled port and associated Gigabit Ethernet port channel interface. |
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 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 long to be displayed. 0:00:00 indicates the counters were cleared more than 231 ms and less than 232 ms ago. |
Input queue |
Number of packets in the input queue and the maximum size of the queue. |
Queueing strategy |
First-in, first-out 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 and the maximum size of the queue. |
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. Broadcast storms on Ethernet lines 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 for the medium. |
giants |
Number of packets that are discarded because they exceed the maximum packet size for the medium. |
input errors |
Total number of no buffer, runts, giants, cyclic redundancy checks (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 |
CRC 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. 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 pass received data to a hardware buffer because the input rate exceeded the receiver's capacity for handling 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. |
watchdog |
Number of times the watchdog receive timer expired. |
multicast |
Number of multicast packets received. |
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, the system periodically resets the interface in an effort to restart that interface. 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 |
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. |
PAUSE output |
Not supported. |
output buffer failures |
Number of times that a packet was not output from the output hold queue because of a shortage of 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. |
The following example shows how to configure Gigabit Ethernet ports 2/0 and 4/0 into port channel 1 with LACP parameters.
Router> enable Router# configure terminal Router(config)# lacp system-priority 65535 Router(config)# interface port-channel 1 Router(config-if)# lacp max-bundle 1 Router(config-if)# ip address 10.1.1.1 255.255.255.0 Router(config)# interface gigabitethernet 2/0/0 Router(config-if)# no ip address Router(config-if)# lacp port-priority 100 Router(config-if)# channel-group 1 mode passive Router(config-if)# exit Router(config)# interface gigabitethernet 4/0/0 Router(config-if)# no ip address Router(config-if)# lacp port-priority 200 Router(config-if)# channel-group 1 mode passive Router(config-if)# end
This example shows how to configure channel group number 5 and include it in the channel group.
Router1# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router1(config)# interface port 5 Router1(config-if)# *Aug 20 17:06:14.417: %LINEPROTO-5-UPDOWN: Line protocol on Interface Port-channel5, changed state to down *Aug 20 17:06:25.413: %LINK-3-UPDOWN: Interface Port-channel5, changed state to down Router1(config-if)# Router1(config-if)# interface gigabitethernet 7/0/0 Router1(config-if)# channel-group 5 mode active Router1(config-if)# *Aug 20 17:07:43.713: %LINK-3-UPDOWN: Interface GigabitEthernet7/0/0, changed state to down *Aug 20 17:07:44.713: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet7/0/0, changed state to down *Aug 20 17:07:45.093: %C10K_ALARM-6-INFO: ASSERT CRITICAL GigE 7/0/0 Physical Port Link Down *Aug 20 17:07:45.093: %C10K_ALARM-6-INFO: CLEAR CRITICAL GigE 7/0/0 Physical Port Link Down *Aug 20 17:07:47.093: %LINK-3-UPDOWN: Interface GigabitEthernet7/0/0, changed state to up *Aug 20 17:07:48.093: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet7/0/0, changed state to up *Aug 20 17:07:48.957: GigabitEthernet7/0/0 added as member-1 to port-channel5 *Aug 20 17:07:51.957: %LINEPROTO-5-UPDOWN: Line protocol on Interface Port-channel5, changed state to up Router1(config-if)# end Router1# *Aug 20 17:08:00.933: %SYS-5-CONFIG_I: Configured from console by console Router1# show lacp 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 Gi7/0/0 SA bndl 32768 0x5 0x5 0x43 0x3D Router1# show interface port 5 Port-channel5 is up, line protocol is up Hardware is GEChannel, address is 0014.a93d.4aa8 (bia 0000.0000.0000) 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) ARP type: ARPA, ARP Timeout 04:00:00 No. of active members in this channel: 1 Member 0 : GigabitEthernet7/0/0 , Full-duplex, 1000Mb/s Last input 00:00:05, 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 Interface Port-channel5 queueing strategy: PXF First-In-First-Out Output queue 0/8192, 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 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 9 packets output, 924 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 PAUSE output 0 output buffer failures, 0 output buffers swapped out Router1#
The following example shows how to add an interface to a bundle:
Router1# Router1# show lacp 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 Gi7/0/0 SA bndl 32768 0x5 0x5 0x43 0x3D Router1# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router1(config)# interface gigabitethernet 5/0/0 Router1(config-if)# channel-group 5 mode active Router1(config-if)# *Aug 20 17:10:19.057: %LINK-3-UPDOWN: Interface GigabitEthernet5/0/0, changed state to down *Aug 20 17:10:19.469: %C10K_ALARM-6-INFO: ASSERT CRITICAL GigE 5/0/0 Physical Port Link Down *Aug 20 17:10:19.473: %C10K_ALARM-6-INFO: CLEAR CRITICAL GigE 5/0/0 Physical Port Link Down *Aug 20 17:10:21.473: %LINK-3-UPDOWN: Interface GigabitEthernet5/0/0, changed state to up *Aug 20 17:10:21.473: GigabitEthernet7/0/0 taken out of port-channel5 *Aug 20 17:10:23.413: GigabitEthernet5/0/0 added as member-1 to port-channel5 *Aug 20 17:10:23.473: %LINK-3-UPDOWN: Interface Port-channel5, changed state to up Router1(config-if)# end Router1# *Aug 20 17:10:27.653: %SYS-5-CONFIG_I: Configured from console by console *Aug 20 17:11:40.717: GigabitEthernet7/0/0 added as member-2 to port-channel5 Router1# show lacp 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 Gi7/0/0 SA bndl 32768 0x5 0x5 0x43 0x3D Gi5/0/0 SA bndl 32768 0x5 0x5 0x42 0x3D Router1# Router1# show interface port 5 Port-channel5 is up, line protocol is up Hardware is GEChannel, address is 0014.a93d.4aa8 (bia 0000.0000.0000) MTU 1500 bytes, BW 2000000 Kbit, DLY 10 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) ARP type: ARPA, ARP Timeout 04:00:00 No. of active members in this channel: 2 Member 0 : GigabitEthernet5/0/0 , Full-duplex, 1000Mb/s <---- added to port channel bundle Member 1 : GigabitEthernet7/0/0 , Full-duplex, 1000Mb/s Last input 00:00:00, output never, output hang never Last clearing of "show interface" counters never Input queue: 0/150/0/0 (size/max/drops/flushes); Total output drops: 0 Interface Port-channel5 queueing strategy: PXF First-In-First-Out Output queue 0/8192, 0 drops; input queue 0/150, 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 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 104 packets output, 8544 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 PAUSE output 0 output buffer failures, 0 output buffers swapped out Router1#
The following example shows how to remove an interface from a bundle:
Router1# Router1# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router1(config)# interface gigabitethernet 7/0/0 Router1(config-if)# no channel-group 5 mode active Router1(config-if)# *Aug 20 17:15:49.433: GigabitEthernet7/0/0 taken out of port-channel5 *Aug 20 17:15:49.557: %C10K_ALARM-6-INFO: ASSERT CRITICAL GigE 5/0/0 Physical Port Link Down *Aug 20 17:15:50.161: %C10K_ALARM-6-INFO: CLEAR CRITICAL GigE 5/0/0 Physical Port Link Down *Aug 20 17:15:51.433: %LINK-3-UPDOWN: Interface GigabitEthernet7/0/0, changed state to down *Aug 20 17:15:52.433: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet7/0/0, changed state to down Router1(config-if)# end Router1# *Aug 20 17:15:58.209: %SYS-5-CONFIG_I: Configured from console by console Router1# *Aug 20 17:15:59.257: %C10K_ALARM-6-INFO: ASSERT CRITICAL GigE 7/0/0 Physical Port Link Down *Aug 20 17:15:59.257: %C10K_ALARM-6-INFO: CLEAR CRITICAL GigE 7/0/0 Physical Port Link Down Router1# *Aug 20 17:16:01.257: %LINK-3-UPDOWN: Interface GigabitEthernet7/0/0, changed state to up *Aug 20 17:16:02.257: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet7/0/0, changed state to up Router1# show lacp 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 Router1#
The following example shows LACP activity that you can monitor by using the show lacp command.
Router1# show lacp 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 Router1# 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 Router1# 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 Router1# show lacp 5 neighbor 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 neighbors Partner's information: Partner Partner LACP Partner Partner Partner Partner Partner Port Flags State Port Priority Admin Key Oper Key Port Number Port State Gi5/0/0 SP 32768 0011.2026.7300 11s 0x1 0x14 0x3C Router1# show lacp counters LACPDUs Marker Marker Response LACPDUs Port Sent Recv Sent Recv Sent Recv Pkts Err --------------------------------------------------------------------- Channel group: 5 Gi5/0/0 23 20 0 0 0 0 0 Router1# show lacp sys-id 32768,0014.a93d.4a00 Router1#
The following example shows how to display the configuration of port channel interface 1.
Router# show interface port-channel 1
Port-channel1 is up, line protocol is up
Hardware is GEChannel, address is 0013.19b3.7748 (bia 0000.0000.0000)
MTU 1500 bytes, BW 2000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
ARP type: ARPA, ARP Timeout 04:00:00
No. of active members in this channel: 2
Member 0 : GigabitEthernet3/0/0 , Full-duplex, 1000Mb/s Member 1 : GigabitEthernet7/1/0 , Full-duplex, 1000Mb/s
Last input 00:00:05, output never, output hang never
Last clearing of "show interface" counters 00:04:40
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Interface Port-channel1 queueing strategy: PXF First-In-First-Out
Output queue 0/8192, 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 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
3 packets output, 180 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 PAUSE output
0 output buffer failures, 0 output buffers swapped out
Related Topic |
Document Title |
---|---|
Configuring EtherChannels |
"Configuring Layer 3 and Layer 2 EtherChannel" chapter of the Catalyst 6500 Release 12.2SXF Software Configuration Guide |
LACP commands |
Cisco IOS Carrier Ethernet Command Reference |
LACP commands: complete command syntax, command mode, command history, defaults, usage guidelines, and examples |
Cisco IOS Network Management Command Reference |
Cisco IOS commands: master list of commands with complete command syntax, command mode, command history, defaults, usage guidelines, and examples |
Standard |
Title |
---|---|
IEEE 802.3ad-2000 |
IEEE 802.3ad-2000 Link Aggregation |
MIB |
MIBs Link |
---|---|
No new or modified MIBs are supported, and support for existing MIBs has not been modified |
To locate and download MIBs for selected platforms, Cisco software releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFC |
Title |
---|---|
No new or modified RFCs are supported, and support for existing RFCs has not been modified. |
-- |
Description |
Link |
---|---|
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 3 | Feature Information for Configuring IEEE 802.3ad Link Bundling |
Feature Name |
Releases |
Feature Information |
---|---|---|
EtherChannel Min-Links |
Cisco IOS XE Release 2.5 |
The EtherChannel Min-Links feature allows a port channel to be shut down when the number of active links falls below the minimum threshold. Using the lacp min-bundle command, you can configure the minimum threshold. The following commands were introduced or modified: lacp min-bundle. |
IEEE 802.3ad Faster Link Switchover Time |
Cisco IOS XE Release 2.5 |
The IEEE 802.3ad Faster Link Switchover Time feature provides a link failover time of 250 milliseconds or less and a maximum link failover time of 2 seconds. Also, port channels remain in the LINK_UP state to eliminate reconvergence by the Spanning-Tree Protocol. The following commands were introduced or modified: lacp fast-switchover. |
IEEE 802.3ad Link Aggregation (LACP) |
Cisco IOS XE Release 2.4 |
The IEEE 802.3ad Link Aggregation feature provides a method for aggregating multiple Ethernet links into a single logical channel based on the IEEE 802.3ad standard. In addition, this feature provides a capability to dynamically provision, manage, and monitor various aggregated links and enables interoperability between various Cisco devices and devices of third-party vendors. In Cisco IOS XE Release 2.4, this feature was implemented on the Cisco ASR1000 Series Router. The following commands were introduced or modified: channel-group (interface), debug lacp, lacp max-bundle, lacp port-priority, lacp system-priority, show lacp. |
Link Aggregation Control Protocol (LACP) (802.3ad) for Gigabit Interfaces |
Cisco IOS XE Release 2.5 |
The LACP (802.3ad) for Gigabit Interfaces feature bundles individual Gigabit Ethernet links into a single logical link that provides the aggregate bandwidth of up to four physical links. The following commands were introduced or modified: lacp max-bundle. |
SSO - LACP |
Cisco IOS XE Release 2.5 |
The SSO - LACP feature supports stateful switchover (SSO), in service software upgrade (ISSU), Cisco nonstop forwarding (NSF), and nonstop routing (NSR) on Gigabit EtherChannel bundles. This feature uses no new or modified commands. |
Cisco and the Cisco Logo are trademarks of Cisco Systems, Inc. and/or its affiliates in the U.S. and other countries. A listing of Cisco's trademarks can be found at www.cisco.com/go/trademarks. Third party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1005R)
Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.