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Cisco IOS Interface and Hardware Component Command Reference
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Introduction
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A through B
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cable bundle through clock mode
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clock rate through cut-through
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D through E
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F through H
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I through K
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l2 vfi manual through loopback (PA-MC-8TE1 + port adapter)
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loopback (T1 interface) through nrzi-encoding
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O through R
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scramble through service-module t1 lbo
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service-module t1 linecode through show controllers satellite
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show controllers serial through show hw-module slot proc cpu
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show hw-module slot tech-support through show interfaces vg-anylan
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show interfaces vlan mapping through show scp
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show service-module serial through standby port
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squelch through system jumbomtu
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t1 through tug-2 e1 unframed
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tunnel bandwidth through yellow
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Table Of Contents
l2protocol-tunnel drop-threshold
l2protocol-tunnel global drop-threshold
l2protocol-tunnel shutdown-threshold
lacp active-port distribution automatic
logging event link-status (global configuration)
logging event link-status (interface configuration)
logging event subif-link-status
logging-events (T1-E1 controller)
loopback (PA-MC-8TE1+ port adapter)
l2 vfi manual
To create a Layer 2 virtual forwarding instance (VFI) and enter Layer 2 VFI manual configuration mode, use the l2 vfi manual command in global configuration mode. To remove the Layer 2 VFI, use the no form of this command.
l2 vfi name manual
no l2 vfi name manual
Syntax Description
Defaults
The Layer 2 VFI is not configured.
Command Modes
Global configuration (config)
Command History
Usage Guidelines
A VFI is a collection of data structures used by the data plane, software-based or hardware-based, to forward packets to one or more virtual circuits (VC). It is populated and updated by both the control plane and the data plane and also serves as the data structure interface between the control plane and the data plane.
Within the Layer 2 VFI manual configuration mode, you can configure the following parameters:
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VPN ID of a Virtual private LAN service (VPLS) domain
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•
Within the Layer 2 VFI manual configuration mode, the following commands are available:
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Examples
This example shows how to create a Layer 2 VFI, enter Layer 2 VFI manual configuration mode, and configure a VPN ID:
Router(config)# l2 vfi vfitest1 manualRouter(config-vfi)# vpn id 303Related Commands
l2protocol-tunnel
To enable the protocol tunneling on an interface and specify the type of protocol to be tunneled, use the l2protocol-tunnel command in interface configuration mode. To disable protocol tunneling, use the no form of this command.
l2protocol-tunnel [cdp | stp | vtp]
no l2protocol-tunnel [cdp | stp | vtp]
Syntax Description<
cdp
(Optional) Enables Cisco Discovery Protocol (CDP) tunneling.
stp
(Optional) Enables Spanning Tree Protocol (STP) tunneling.
vtp
(Optional) Enables VLAN Trunking Protocol (VTP) tunneling.
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
On all the service provider edge switches, you must enable PortFast BPDU filtering on the 802.1Q tunnel ports by entering these commands:
Router(config-if)# spanning-tree bpdufilter enableRouter(config-if)# spanning-tree portfast
Note
If you do not specify a protocol, all protocols are tunneled.
You can configure protocol tunneling on VLAN and trunk interfaces.
You must enter the switchport command once without any keywords to configure the LAN port 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.
Examples
This example shows how to enable a tunneling protocol on an interface:
Router(config-if)# l2protocol-tunnel cdpRouter(config-if)#This example shows how to disable a tunneling protocol on an interface:
Router(config-if)# no l2protocol-tunnelProtocol tunneling disabled on interface fastEthernet 4/1Router(config-if)#Related Commands
l2protocol-tunnel cos
To specify a class of service (CoS) value globally on all ingress Layer-2 protocol tunneling ports, use the l2protocol-tunnel cos command in global configuration mode. To return to the default , use the no form of this command.
l2protocol-tunnel cos cos-value
no l2protocol-tunnel cos
Syntax Description
Defaults
The cos-value is 5.
Command Modes
Global configuration
Command History
Usage Guidelines
The cos-value is the CoS value that you assign to the PDUs on a Layer 2-protocol tunnel port before tunneling the PDUs through the service-provider network.
You can specify a CoS value globally on all ingress Layer 2-protocol tunneling ports. Because the CoS value applies to all ingress tunneling ports, all encapsulated PDUs that are sent out by the Catalyst 6500 series switch have the same CoS value.
On all the service-provider edge switches, you must enable PortFast BPDU filtering on the 802.1Q tunnel ports by entering these commands:
Router(config-if)# spanning-tree bpdufilter enableRouter(config-if)# spanning-tree portfast
Note
Examples
This example shows how to specify a CoS value on all ingress Layer 2-protocol tunneling ports:
Router(config)# l2protocol-tunnel cos 6Router(config)#Related Commands
show l2protocol-tunnel
Displays the protocols that are tunneled on an interface or on all interfaces.
l2protocol-tunnel drop-threshold
To specify the maximum number of packets that can be processed for the specified protocol on that interface before being dropped, use the l2protocol-tunnel drop-threshold command in interface configuration mode. To reset all the threshold values to 0 and disable the drop threshold, use the no form of this command.
l2protocol-tunnel drop-threshold [cdp | stp | vtp] packets
no l2protocol-tunnel drop-threshold [cdp | stp | vtp]
Syntax Description
cdp
(Optional) Specifies CDP packets.
stp
(Optional) Specifies STP packets.
vtp
(Optional) Specifies VTP packets.
packets
Maximum number of packets; valid values are from 1 to 4096 packets.
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
On all the service-provider edge switches, you must enable PortFast BPDU filtering on the 802.1Q tunnel ports by entering these commands:
Router(config-if)# spanning-tree bpdufilter enableRouter(config-if)# spanning-tree portfast
Note
If you do not specify a protocol, the threshold applies to all protocols.
You can configure protocol tunneling on switch ports only. You must enter the switchport command once without any keywords to configure the LAN port 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.
Refer to the "Configuring IEEE 802.1Q Tunneling and Layer 2 Protocol Tunneling" chapter of the Cisco 7600 Series Router Cisco IOS Software Configuration Guide for additional information on setting the drop threshold value.
Examples
This example shows how to set the drop threshold:
Router(config-if)# switchportRouter(config-if)# l2protocol-tunnel drop-threshold 3000Router(config-if)#Related Commands
l2protocol-tunnel global drop-threshold
To enable rate limiting at the software level, use the l2protocol-tunnel global drop-threshold command in global configuration mode. To disable the software rate limiter on the Catalyst 6500 series switch, use the no form of this command.
l2protocol-tunnel global drop-threshold threshold
no l2protocol-tunnel global drop-threshold
Syntax Description
threshold
Maximum rate of incoming PDUs before excessive PDUs are dropped; valid values are from 100 to 20000 PDUs.
Defaults
Global thresholds are not configured.
Command Modes
Global configuration
Command History
12.2(17a)SX
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.
Usage Guidelines
This command is not supported on Cisco 7600 series routers that are configured with a Supervisor Engine 2.
All three PDUs (normal BPDU, CDP, and VTP packets) that arrive on Layer 2-protocol tunnel-enabled ports are rate limited. Rate limiting occurs in the ingress direction in Layer 2-protocol tunneling. If the rate of the incoming PDUs exceeds the configured threshold, the excessive PDUs are dropped.
Examples
This example shows how to enable rate limiting globally:
Router(config)# l2protocol-tunnel global drop-threshold 3000Router(config)#Related Commands
l2protocol-tunnel shutdown-threshold
To specify the maximum number of packets that can be processed for the specified protocol on that interface in 1 second, use the l2protocol-tunnel shutdown-threshold command in interface configuration mode. To reset all the threshold values to 0 and disable the shutdown threshold, use the no form ofthis command.
l2protocol-tunnel shutdown-threshold [cdp | stp | vtp] packets
no l2protocol-tunnel shutdown-threshold [cdp | stp | vtp] packets
Syntax Description
cdp
(Optional) Specifies CDP tunneling.
stp
(Optional) Specifies STP tunneling.
vtp
(Optional) Specifies VTP tunneling.
packets
Shutdown threshold; valid values are from 1 to 4096.
Defaults
This command has no default settings.
Command Modes
Interface configuration
Command History
Usage Guidelines
When the number of packets is exceeded, the port is put in error-disabled state.
On all the service-provider edge switches, you must enable PortFast BPDU filtering on the 802.1Q tunnel ports by entering these commands:
Router(config-if)# spanning-tree bpdufilter enableRouter(config-if)# spanning-tree portfast
Note
If you do not specify a protocol, the packets value applies to all protocols.
You can configure protocol tunneling on switch ports only. You must enter the switchport command once without any keywords to configure the LAN port 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.
Refer to the "Configuring IEEE 802.1Q Tunneling and Layer 2 Protocol Tunneling" chapter of the Cisco 7600 Series Router Cisco IOS Software Configuration Guide for additional information on setting the drop threshold value.
Examples
This example shows how to specify the maximum number of CDP packets that can be processed on that interface in 1 second:
Router(config-if)# switchportRouter(config-if)# l2protocol-tunnel shutdown-threshold cdp 200Router(config-if)#Related Commands
l3vpn encapsulation ip
To configure an L3VPN encapsulation profile, use the l3vpn encapsulation ip command in global configuration mode. To remove the encapsulation profile, use the no form of this command.
l3vpn encapsulation ip profile name
no l3vpn encapsulation ip profile name
Syntax Description
Command Default
The L3VPN encapsulation profile is not configured.
Command Modes
Global configuration (config)
Command History
Usage Guidelines
When you use the l3vpn encapsulation ip command you enter into L3VPN encapsulation configuration mode. You can then specify the transport source mode and interface using the transport ipv4 command, set the GRE key using the protocol gre command, and configure the L3VPN encapsulation profile.
Examples
The following example shows how to configure an L3VPN encapsulation profile:
Router(config)# l3vpn encapsulation ip tunnelencapRelated Commands
lacp active-port distribution automatic
To have an effective auto interleaved port priority distribution of active and bundled ports across different slots that are part of the same port channel distributed EtherChannel (DEC) and multichassis EtherChannel (MEC), use the lacp active-port distribution automatic command in port channel configuration mode.
lacp active-port distribution automatic
no lacp active-port distribution automatic
Syntax Description
This command has no keywords or arguments.
Command Default
Auto interleaved port priority is disabled.
Command Modes
Interface configuration (config-if)
Command History
Usage Guidelines
The auto interleaved port-priority feature automatically distributes active and bundled ports based on the position of a port link when it comes up and is effective only if you configure it on the system that has the higher LACP system priority.
The port priority per port that you configured continues to take precedence over a dynamic port number. You need to perform a shutdown and no shutdown on the interface port channel to enable the auto interleaved port priority feature on all ports.
Examples
This example shows how to configure interleaved port priority:
Router(config)# interface port23Router(config-if)# lacp active-port distribution automaticPlease shut/no shut the port-channel for configuration to take effect immediately.Router(config-if)# shutdownRouter(config-if)# no shutdownRouter(config-if)# endThis example shows how to verify that interleaved port priority is configured:
Router# show running interface port23Building configuration...Current configuration : 81 bytes!interface Port-channel23no switchportno ip addresslacp max-bundle 4lacp active-port distribution automaticendRouter# show etherchannel 23 summaryFlags: D - down P - bundled in port-channelI - stand-alone s - suspendedH - Hot-standby (LACP only)R - Layer3 S - Layer2U - in use N - not in use, no aggregationf - failed to allocate aggregatorM - not in use, no aggregation due to minimum links not metm - not in use, port not aggregated due to minimum links not metu - unsuitable for bundlingd - default portw - waiting to be aggregatedNumber of channel-groups in use: 9Number of aggregators: 9Group Port-channel Protocol Ports------+-------------+-----------+-----------------------------------------------23 Po23(RU) LACP Gi1/1/21(P) Gi1/1/22(P) Gi1/1/23(P)Gi1/1/24(P) Gi2/1/17(H) Gi2/1/18(H)Gi2/1/19(H) Gi2/1/20(H)Last applied Hash Distribution Algorithm: Fixed
Note
Related Commands
lacp fast-switchover
To enable Link Aggregation Control Protocol (LACP) 1:1 link redundancy, use the lacp fast-switchover command in interface configuration mode. To disable LACP 1:1 link redundancy, use the no form of this command.
lacp fast-switchover
no lacp fast-switchover
Syntax Description
This command has no arguments or keywords.
Command Default
LACP 1:1 link redundancy is disabled by default.
Command Modes
Interface configuration (config-if)
Command History
Usage Guidelines
Prior to entering the lacp fast-switchover command, you must ensure the following:
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•
When you enable LACP 1:1 link redundancy, based on the system priority and port priority, the port with the higher system priority chooses the link as the active link and the other link as the standby link. When the active link fails, the standby link is selected as the new active link without taking down the port channel. When the original active link recovers, it reverts to its active link status. During this change-over, the port channel is also up.
Note
You can enter this command on any port channels with different EtherChannel protocol types of LACP, Port Aggregation Protocol (PAgP), or Fast EtherChannel (FEC).
Examples
This example shows how to enable LACP 1:1 link redundancy:
Router(config-if)# lacp fast-switchoverThis example shows how to disable LACP 1:1 link redundancy:
Router(config-if)# no lacp fast-switchoverRelated Commands
lacp max-bundle
Assigns and configures an EtherChannel interface to an EtherChannel group.
show etherchannel
Displays the EtherChannel information for a channel.
lacp max-bundle
To define the maximum number of bundled Link Aggregation Control Protocol (LACP) ports allowed in a port channel, use the lacp max-bundle command in interface configuration mode. To return to the default settings, use the no form of this command.
lacp max-bundle max-bundles
no lacp max-bundle
Syntax Description
max-bundles
Maximum number of bundled ports allowed in the port channel. Valid values are from 1 to 8.
Note
Defaults
The default settings are as follows:
•
•
•
Command Modes
Interface configuration
Command History
Usage Guidelines
Cisco 10000 Series Router
This command requires a Performance Routing Engine 2 (PRE2) or PRE3.
Examples
This example shows how to set 3 ports to bundle in a port channel:
Router(config-if)# lacp max-bundle 3Router(config-if)#Related Commands
lacp port-priority
To set the priority for a physical interface, use the lacp port-priority command in interface configuration mode. To return to the default setting, use the no form of this command.
lacp port-priority priority
no lacp port-priority
Syntax Description
priority
Integer from 1 to 65535 that indicates the priority for the physical interface. The default is 32768.
Command Default
The default port priority is set.
Command Modes
Interface configuration (config-if)
Command History
Usage Guidelines
You must assign a port priority to each port on a device running Link Aggregation Control Protocol (LACP). You can specify the port priority by using the lacp port-priority command at the command-line interface (CLI) or use the default port priority (32768) that is carried as part of the LACP protocol data unit (PDU) exchanged with the partner. Port priority is used to decide which ports should be put in standby mode when a hardware limitation prevents all compatible ports from aggregating. Priority is supported only on port channels with LACP-enabled physical interfaces.
Note
Port priority together with port number forms a port identifier.
Examples
This example shows how to set a priority of 23700 for an interface:
Router(config-if)# lacp port-priority 23700Router(config-if)#Related Commands
lacp rate
To set the rate at which Link Aggregation Control Protocol (LACP) control packets are ingressed to an LACP-supported interface, use the lacp rate command in interface configuration mode. To return to the default settings, use the no form of this command.
lacp rate {normal | fast}
no lacp rate
Syntax Description
Defaults
The default ingressed rate for control packets is 30 seconds after the link is bundled.
Command Modes
Interface configuration (config-if)
Command History
12.2(18)SXF2
This command was introduced on the Catalyst 6500 series switch.
12.2(33)SRC
This command was integrated into Cisco IOS Release 12.2(33)SRC.
Usage Guidelines
Use this command to modify the duration of a LACP timeout. The LACP timeout value is set on Cisco switches to a value of 90 seconds. Using the lacp rate command, you can select the LACP timeout value for a switch to be either 30 seconds or 1 second.
This command is supported only on LACP-enabled interfaces.
Examples
This example shows how to specify the fast (1-second) ingress rate on interface Ethernet 0/1:
Router(config)# interface ethernet 0/1Router(config-if)# lacp rate fastRelated Commands
lacp system-priority
To set the priority for a system, use the lacp system-priority command in global configuration mode or in interface configuration mode. To return to the default setting, use the no form of this command.
lacp system-priority priority
no lacp system-priority
Syntax Description
Command Default
The default system priority is set.
Command Modes
Global configuration
Interface configurationCommand History
Usage Guidelines
You must assign a system priority to each device running Link Aggregation Control Protocol (LACP). You can specify the system priority by using the lacp system-priority command at the command-line interface (CLI) or use the default system priority (32768) that is carried as part of the LACP protocol data unit (PDU) exchanged with the partner. System priority is used with the MAC address of the device to form the system ID and also is used during negotiation with other systems. Priority is supported only on port channels with LACP-enabled physical interfaces.
Note
The lacp system-priority command can also be issued in interface configuration mode. After you enter the command, the system returns to global configuration mode.
Examples
The following example shows how to set a system priority of 25500 for a device:
Router(config)# lacp system-priority 25500Related Commands
lbo
To set a cable length longer than 655 feet for a DS-1 link, use the lbo command in interface configuration mode on the interface for a T1 link. To delete the lbo value, use the no form of this command.
lbo {long {gain26 | gain36} {-15db | -22.5db | -7.5db | 0db} | short {133 | 266 | 399 | 533 | 655}}
no lbo
Syntax Description
Defaults
gain26 and 0db
Command Modes
Interface configuration
Command History
Usage Guidelines
This command is supported on T1 links only.
Each T1 port can operate in long-haul or short-haul mode. In long haul mode, the user must specify the gain and the line build out. In short-haul mode, the user must specify the cable length in feet.
The transmit attenuation value is best obtained by experimentation. If the signal received by the far-end equipment is too strong, reduce the transmit level by entering additional attenuation.
Examples
On Cisco 7100 or Cisco 7200 series routers, the following example specifies a pulse gain of 36 decibels and a decibel pulse rate of -7.5 decibels:
Router(config)# interface atm 1/2Router(config-if)# lbo long gain36 -7.5dblex burned-in-address
To set the burned-in MAC address for a LAN Extender interface, use the lex burned-in-address command in interface configuration mode. To clear the burned-in MAC address, use the no form of this command.
lex burned-in-address ieee-address
no lex burned-in-address
Syntax Description
Defaults
No burned-in MAC address is set.
Command Modes
Interface configuration
Command History
Usage Guidelines
Use this command only on a LAN Extender interface that is not currently active (not bound to a serial interface).
Examples
The following example sets the burned-in MAC address on LAN Extender interface 0:
Router(config)# interface serial 4Router(config-if)# encapsulation pppRouter(config)# interface lex 0Router(config-if)# lex burned-in-address 0000.0c00.0001Router(config-if) ip address 10.108.172.21 255.255.255.0lex input-address-list
To assign an access list that filters on MAC addresses, use the lex input-address-list command in interface configuration mode. To remove an access list from the interface, use the no form of this command.
lex input-address-list access-list-number
no lex input-address-list
Syntax Description
access-list-number
Number of the access list assigned with the access-list global configuration command. It can be a number from 700 to 799.
Defaults
No access lists are preassigned to a LAN Extender interface.
Command Modes
Interface configuration
Command History
Usage Guidelines
Use the lex input-address-list command to filter the packets that are allowed to pass from the LAN Extender to the core router. The access list filters packets on the basis of the source MAC address.
The LAN Extender interface does not process MAC-address masks. Therefore, you should omit the mask from the access-list commands.
For LAN Extender interfaces, an implicit permit everything entry is automatically defined at the end of an access list. Note that this default differs from other access lists, which have an implicit deny everything entry at the end of each access list.
Examples
The following example applies access list 710 to LAN Extender interface 0. This access list denies all packets from MAC address 0800.0214.2776 and permits all other packets.
Router(config-if)# access-list 710 deny 0800.0214.2776Router(config)# interface lex 0Router(config-if)# lex input-address-list 710Related Commands
access-list
Configures the access list mechanism for filtering frames by protocol type or vendor code.
lex input-type-list
To assign an access list that filters Ethernet packets by type code, use the lex input-type-list command in interface configuration mode. To remove an access list from an interface, use the no form of this command.
lex input-type-list access-list-number
no lex input-type-list
Syntax Description
access-list-number
Number of the access list that you assigned with the access-list command. It can be a number in the range 200 to 299.
Defaults
No access lists are preassigned to a LAN Extender interface.
Command Modes
Interface configuration
Command History
Usage Guidelines
Filtering is done on the LAN Extender chassis.
The LAN Extender interface does not process masks. Therefore, you should omit the mask from the access-list commands.
For LAN Extender interfaces, an implicit permit everything entry is automatically defined at the end of an access list. Note that this default differs from other access lists, which have an implicit deny everything entry at the end of each access list.
Examples
The following example applies access list 220 to LAN Extender interface 0. This access list denies all AppleTalk packets (packets with a type field of 0x809B) and permits all other packets.
Router(config-if)# access-list 220 deny 0x809B 0x0000Router(config)# interface lex 0Router(config-if)# lex input-type-list 220Related Commands
access-list
Configures the access list mechanism for filtering frames by protocol type or vendor code.
lex priority-group
To activate priority output queueing on the LAN Extender, use the lex priority-group command in interface configuration mode. To disable priority output queueing, use the no form of this command.
lex priority-group group
no lex priority-group
Syntax Description
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
To define queueing priorities, use the priority-list protocol global configuration command. Note that you can use only the following forms of this command:
priority-list list protocol protocol {high | medium | normal | low}
priority-list list protocol bridge {high | medium | normal | low} list list-number
If you specify a protocol that does not have an assigned Ethernet type code, such as x25, stun, or pad, it is ignored and will not participate in priority output queueing.
Examples
The following example activates priority output queueing on LAN Extender interface 0:
Router(config-if)# priority-list 5 protocol bridge medium list 701Router(config-if)# lex interface 0Router(config-if)# lex priority-group 5Related Commands
priority-list protocol
Establishes queueing priorities based on the protocol type.
lex retry-count
To define the number of times to resend commands to the LAN Extender chassis, use the lex retry-count command in interface configuration mode. To return to the default value, use the no form of this command.
lex retry-count number
no lex retry-count number
Syntax Description
number
Number of times to retry sending commands to the LAN Extender. It can be a number in the range 0 to 100. The default is 10.
Defaults
10 retries
Command Modes
Interface configuration
Command History
Usage Guidelines
After the router has sent a command the specified number of times without receiving an acknowledgment from the LAN Extender, it stops sending the command altogether.
Examples
The following example resends commands 20 times to the LAN Extender:
Router(config-if)# lex interface 0Router(config-if)# lex retry-count 20Related Commands
lex timeout
Defines the amount of time to wait for a response from the LAN Extender.
lex timeout
To define the amount of time to wait for a response from the LAN Extender, use the lex timeout command in interface configuration mode. To return to the default time, use the no form of this command.
lex timeout milliseconds
no lex timeout [milliseconds]
Syntax Description
milliseconds
Time, in milliseconds, to wait for a response from the LAN Extender before resending the command. It can be a number in the range 500 to 60,000. The default is 2000 ms.
Defaults
2000 ms (2 seconds)
Command Modes
Interface configuration
Command History
Usage Guidelines
The lex timeout command defines the amount of time that the router waits to receive an acknowledgment after having sent a command to the LAN Extender.
Examples
The following example causes unacknowledged packets to be resent at 4-second intervals:
Router(config-if)# lex interface 0Router(config-if)# lex timeout 4000Related Commands
lex retry-count
Defines the number of times to resend commands to the LAN Extender chassis.
linecard-group y-cable
To create a line card group for one-to-one line card redundancy, use the linecard-group y-cable command in redundancy mode. To remove the line card redundancy group, use the no form of this command.
linecard-group linecard-groupId y-cable
no linecard-group linecard-groupId y-cable
Syntax Description
linecard-groupId
An unsigned integer in the range 0 to the (maximum number of chassis line card subslots/2) -1.
y-cable
The link protection type for the line card group.
Command Default
No default behavior or values.
Command Modes
Redundancy
Command History
Usage Guidelines
The no linecard-group y-cable command removes the line card redundancy group and frees the linecard-groupId for reuse. The no linecard-group y-cable command succeeds only if there are no subslot members in the line card redundancy group.
Examples
The following example creates line card group number 1 for one-to-one line card redundancy:
Router(config)# redundancyRouter(config-red)# linecard-group 1 y-cableRelated Commands
linecode
To select the line-code type for T1 or E1 lines, use the linecode command in controller configuration mode.
linecode {ami | b8zs | hdb3}
Syntax Description
Defaults
AMI is the default for T1 lines.
High-density bipolar 3 is the default for E1 lines.Command Modes
Controller configuration
Command History
Usage Guidelines
Use this command in configurations in which the router or access server must communicate with T1 fractional data lines. The T1 service provider determines which line-code type, either ami or b8zs, is required for your T1 circuit. Likewise, the E1 service provider determines which line-code type, either ami or hdb3, is required for your E1 circuit.
This command does not have a no form.
Examples
The following example specifies B8ZS as the line-code type:
Router(config-controller)# linecode b8zsline-mode
To configure the mode of the controller for the Symmetrical High-Speed Digital Subscriber Line (SHDSL) port, use the line-mode command in controller configuration mode. To return to the default two-wire mode, use the no form of this command.
line-mode [2-wire | 4-wire [enhanced | standard] | auto]
no line-mode
Syntax Description
Defaults
The default is two-wire mode if this command is omitted or if the 4-wire keyword is omitted.
Command Modes
Controller configuration
Command History
Usage Guidelines
This command is used to configure the controller for two-wire or four-wire mode.
Note
Note
Examples
4-Wire Line Mode Example
The following example shows how to configure the controller mode of DSL on the controller in slot 4 and port 0 to operate in four-wire mode:
Router(config)# controller dsl 4/0Router(config-controller)# line-mode 4-wireCPE Line Mode Example
The following example configures the controller in slot 1 and port 0. The router is set to terminate as CPE with the line mode automatically selecting between two-wire mode and four-wire mode.
Router(config)# controller dsl 1/0Router(config-controller)# line-mode autoRouter(config-controller)# line-term cpeRelated Commands
line-rate
Specifies a line rate for the DSL controller.
line-term
Specifies a termination for a line.
line-rate
To specify a line rate for the DSL controller, use the line-rate command in controller configuration mode.
line-rate {auto | rate}
Syntax Description
Defaults
No default behavior or values.
Command Modes
Controller configuration
Command History
Usage Guidelines
This command does not have a no form.
This command specifies the DSL line rate for the Symmetrical High-Speed Digital Subscriber Line (SHDSL) port. Use this command to configure the line rate in two-wire or four-wire mode. The SHDSL rate is in kbps, but the line trains at the selected rate plus two times the 8 kbps of DSL framing overhead.
Note
Note
rate is always the lower rate.
Note
Note
Examples
The following example displays the line-mode command selecting four-wire mode, which is different from the previous line mode of the router as indicated by the router output, and then the line rate is selected. The rate of 4608 is selected, and the output of the router is shown.
Router(config)# controller dsl 1/0Router(config-controller)# line-mode 4-wireRouter(config-controller)#*Jun 15 18:00:48.159: %CONTROLLER-5-UPDOWN: Controller DSL 1/0, changed state tn*Jun 15 18:00:50.159: %LINK-3-UPDOWN: Interface ATM1/0, changed state to down*Jun 15 18:00:51.159: %LINEPROTO-5-UPDOWN: Line protocol on Interface ATM1/0, cnRouter(config-controller)# line-rate 4608Router(config-controller)#*Jun 15 18:01:36.627: %CONTROLLER-5-UPDOWN: Controller DSL 1/0, changed state tn*Jun 15 18:01:36.967: %CONTROLLER-5-UPDOWN: Controller DSL 1/0, changed state tnRouter(config-controller)# exitRelated Commands
line-mode
Configures the mode of the controller.
line-term
Specifies a termination for a line.
line-term
To specify a termination for a line, use the line-term command in controller configuration mode.
line-term {co | cpe}
Syntax Description
Defaults
The default value is cpe.
Command Modes
Controller configuration
Command History
Usage Guidelines
This command does not have a no form.
This command is used to configure the line termination for use as either the central office (CO) or the customer premises equipment (CPE).
Examples
The following example shows how to configure the controller in slot 1 and port 0. The router is set to terminate as CPE with the line mode automatically selecting between two-wire mode and four-wire mode.
Router(config)# controller dsl 1/0Router(config-controller)# line-term cpeRouter(config-controller)# line-mode autoNo change in line modeRelated Commands
line-mode
Configures the mode of the controller.
line-rate
Specifies a line rate for the DSL controller.
line-termination
To set the line termination on an E1 controller, use the line-termination command in controller configuration mode. To return to the default line termination, use the no form of this command.
line-termination {75-ohm | 120-ohm}
no line-termination
Syntax Description
75-ohm
Specifies 75-ohm unbalanced termination.
120-ohm
Specifies 120-ohm balanced termination. This is the default.
Defaults
120-ohms
Command Modes
Controller configuration
Command History
Usage Guidelines
This command applies only to E1 controllers. To determine the line termination setting for the controller, use the show controllers e1 command.
Examples
In the following example, the line termination is set to 75 ohms for the E1 port located in shelf 6, slot 0, port 0:
Router# configure terminalRouter(config)# controller e1 6/0/0Router(config-controller)# line-termination 75-ohmRouter(config-controller)# endRelated Commands
show controllers e1
Displays information about the E1 links supported by the NPM (Cisco 4000) or MIP (Cisco 7500 series).
link debounce
To enable the debounce timer on an interface, use the link debounce command in interface configuration mode. To disable the timer, use the no form of this command.
link debounce [time time]
no link debounce
Syntax Description
time time
(Optional) Specifies the extended debounce timer; valid values are from 100 to 5000 milliseconds.
Defaults
Table 1 lists the debounce timer defaults.
Command Modes
Interface configuration
Command History
Usage Guidelines
The time time keyword and argument are supported on Gigabit Ethernet and 10-Gigabit Ethernet interfaces only.
The link debounce command is not supported on the following modules in releases prior to Release 12.2(17a)SX:
•
•
The debounce timer sets the amount of time that the firmware waits before it notifies the software that the link is down. The debounce timer does not apply to linkup because the linkup is immediately notified by the firmware.
The default debounce time applies when you enter the link debounce command with no arguments. For example, when you enter the link debounce time 100 command, it is equivalent to entering the link debounce command with no arguments and you will see the following link debounce entry in the configuration:
interface GigabitEthernet1/1no ip addresslink debounceEnter the show interfaces debounce command to display the debounce configuration of an interface.
Examples
This example shows how to configure the debounce timer on a Gigabit Ethernet fiber interface:
Router(config-if)# link debounce time 100Router(config-if)#Related Commands
show interfaces debounce
Displays the status and configuration for the debounce timer.
link state group
To configure the link state group, use the link state group command in interface configuration mode.
link state group [number] {upstream | downstream}
Syntax Description
Command Default
The default link state group number is 1.
Command Modes
Interface configuration (config-if)
Command History
Usage Guidelines
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. These are the limitations:
•
•
Examples
The following example shows how to configure the link state group number.
Router# configure terminalRouter(config)# link state track 1Router(config)# interface gigabitethernet3/1Router(config-if)# link state group 1 upstreamRouter(config-if)# interface gigabitethernet3/3Router(config-if)# link state group 1 upstreamRouter(config-if)# interface gigabitethernet3/5Router(config-if)# link state group 1 downstreamRouter(config-if)# interface gigabitethernet3/7Router(config-if)# link state group 1 downstreamRelated Commands
link state track
Configures the link-state track number.
show link state group
Displays the link-state group information.
link state track
To configure a link state tracking number, use the link state track command in global configuration mode. To restore the default link state track number, use the no form of this command.
link state track number
no link state track number
Syntax Description
number
Specifies the link state tracking number. The acceptable range is between 1 and 10 and the default value is 1.
Command Default
The default link state track number is 1.
Command Modes
Global configuration (config)
Command History
Usage Guidelines
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.
Examples
The following example shows how to configure the link state tracking number.
Router# configure terminalRouter(config)# link state track 1Related Commands
link-test
To reenable the link-test function on a port on an Ethernet hub of a Cisco 2505 or Cisco 2507 router, use the link-test command in hub configuration mode. To disable this function, use the no form of this command.
link-test
no link-test
Syntax Description
This command has no arguments or keywords.
Defaults
Enabled
Command Modes
Hub configuration
Command History
Usage Guidelines
This command applies to a port on an Ethernet hub only. Disable this feature if a 10Base-T twisted-pair device at the other end of the hub does not implement the link test function.
Examples
The following example disables the link test function on hub 0, ports 1 through 3:
Router(config)# hub ethernet 0 1 3Router(config-hub)# no link-testRelated Commands
hub
Enables and configures a port on an Ethernet hub of a Cisco 2505 or Cisco 2507 router.
load-balancing
To apply a load-balancing method to a Gigabit EtherChannel (GEC) interface, use the load-balancing command in interface configuration mode. To reset to the default, use the no form of this command.
load-balancing {flow | vlan}
no load-balancing
Syntax Description
Command Default
The port channel uses the global load-balancing configuration.
Command Modes
Interface configuration (config-if)
Command History
Usage Guidelines
The load-balancing command sets the load-balancing method on a specific port channel. The load-balancing method configured with this command takes precedence over the global configuration defined with the port-channel load-balancing vlan-manual command.
If you do not explicitly configure load balancing either globally or on the port channel, the load-balancing method on the port channel is set to flow-based.
Load balancing uses the concept of buckets to map traffic flows to the member links of the port channel. The different traffic flows are mapped to the buckets and each bucket has one active member link associated with it. All flows that are mapped to a bucket use the member link associated with that bucket.
There are two methods of load balancing on a GEC interface:
•
•
Examples
This example shows how to set the load-balancing method to VLAN-manual:
Router(config)# interface port-channel 1Router(config-if)# load-balancing vlanRelated Commands
load-interval
To change the length of time for which data is used to compute load statistics, use the load-interval command in interface configuration mode or Frame Relay DLCI configuration mode. To revert to the default setting, use the no form of this command.
load-interval seconds
no load-interval seconds
Syntax Description
seconds
Length of time for which data is used to compute load statistics. Value is a multiple of 30, from 30 to 600 (30, 60, 90, 120, and so on). The default is 300 seconds.
Command Default
Enabled
Command Modes
Interface configuration
Frame Relay DLCI configurationCommand History
Usage Guidelines
To make computations more reactive to short bursts of traffic, you can shorten the length of time over which load averages are computed.
If the load interval is set to 30 seconds, new data is used for load calculations over a 30-second period. This data is used to compute load statistics, including the input rate in bits and packets per second, the output rate in bits and packets per second, the load, and reliability.
Load data is gathered every five seconds. This data is used for a weighted-average calculation in which recent load data has more weight in the computation than older load data. If the load interval is set to 30 seconds, the average is computed for the last 30 seconds of load data.
If you change the calculation interval from the default of five minutes to a shorter period of time, the input and output statistics that are displayed by the show interface command or the show frame-relay pvc command will be more current and will be based on more nearly instantaneous data, rather than reflecting the average load over a longer period of time.
This command is often used for dial backup purposes to increase or decrease the likelihood of implementation of a backup interface, but it can be used on any interface.
Examples
Interface Example
In the following example, the default average of five minutes is changed to a 30-second average. A burst in traffic that would not trigger a dial backup for an interface configured with the default five-minute interval might trigger a dial backup for this interface, which is set for the shorter 30-second interval.
Router(config)# interface serial 0Router(config-if)# load-interval 30Frame Relay PVC Example
In the following example, the load interval is set to 60 seconds for a Frame Relay PVC with the DLCI 100:
Router(config)# interface serial 1/1Router(config-if)# frame-relay interface-dlci 100Router(config-fr-dlci)# load-interval 60Related Commands
show interfaces
Displays statistics for all interfaces configured on the router or access server.
local ip address
To define an IP address to identify a local circuit emulation (CEM) channel, use the local ip address command in CEM xconnect configuration mode.
local ip address ip-address
Syntax Description
Command Default
The default local IP address is 0.0.0.0 for a CEM channel.
Command Modes
CEM xconnect configuration
Command History
Usage Guidelines
This command does not have a no form. To remove a local IP address, either configure a new local IP address or enter the no xconnect command to disable the connection and all its parameters.
The local IP address used to identify the local end of a CEM connection must be the same as the IP address defined by the remote-ip-address argument used in the xconnect command to identify the CEM channel at the other end of the CEM connection.
Note
local IP address provided that each local IP address defines a unique UDP port number using the
local udp port command.Examples
The following example demonstrates how to configure the IP address of the local endpoint of the CEM over IP (CEoIP) connection.
Router(config-cem-xconnect)# local ip address 10.0.5.1
Related Commands
local udp port
To define the User Datagram Protocol (UDP) port of the local endpoint of a circuit emulation (CEM) connection, use the local udp port command in CEM xconnect configuration mode.
local udp port port
Syntax Description
port
Number of the CEM local UDP port. Possible values are 0, 2141, and 15872 through 16383. The default is 0.
Command Default
The default local UDP port number is 0 for the local endpoint of a CEM connection.
Command Modes
CEM xconnect configuration
Command History
Usage Guidelines
This command does not have a no form. To remove a local UPD port number, either configure a new UPD port number or enter the no xconnect command to disable the connection and all its parameters.
Examples
The following example demonstrates how to configure the UDP port of the local endpoint of the CEM over IP (CEoIP) connection.
Router(config-cem-xconnect)# local udp port 2141
Related Commands
local-lnm
To enable Lanoptics Hub Networking Management of a PCbus Token Ring interface, use the local-lnm command in interface configuration mode. To disable Lanoptics Hub Networking Management, use the no form of this command.
local-lnm
no local-lnm
Syntax Description
This command has no arguments or keywords.
Defaults
Management is not enabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
The Token Ring interface on the AccessPro PC card can be managed by a remote LAN manager over the PCbus interface. At present, the Lanoptics Hub Networking Management software running on an IBM compatible PC is supported.
Examples
The following example enables Lanoptics Hub Networking Management:
Router(config-if)# local-lnmlogging event
To enable notification of interface, subinterface, and Frame Relay data link connection identifier (DLCI) data link status changes, use the logging event command in interface configuration mode. To disable notification, use the no form of this command.
logging event {dlci-status-change | link-status | subif-link-status [ignore-bulk]}
no logging event {dlci-status-change | link-status | subif-link-status [ignore-bulk]}
Syntax Description
Defaults
For system images, notification of interface, subinterface, and Frame Relay DLCI data link status changes is enabled by default.
For boot images, notification of Frame Relay subinterface and DLCI data link status changes is disabled by default. Notification of interface data link status changes is enabled by default.
Command Modes
Interface configuration
Command History
Examples
The following example shows how to enable notification of subinterface link status changes:
Router(config-if)# logging event subif-link-statusThe following are examples of Frame Relay DLCI and subinterface status change notification messages filtered by the logging event command:
00:16:22: %FR-5-DLCICHANGE: Inteface Serial3/0/0:1 - DLCI 105 state changed to INACTIVE00:16:22: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial3/0/0:1.5, changed state to downlogging source-interface
To specify the source IPv4 or IPv6 address of system logging packets, use the logging source-interface command in global configuration mode. To remove the source designation, use the no form of this command.
logging source-interface type number
no logging source-interface
Syntax Description
Command Default
The wildcard interface address is used.
Command Modes
Global configuration (config)
Command History
Usage Guidelines
This command can be configured on the Virtual Routing and Forwarding (VRF) and non-VRF interfaces. Normally, a syslog message contains the IPv4 or IPv6 address of the interface used to leave the router. The logging source-interface command configures the syslog packets contain the IP or IPv6 address of a particular interface, regardless of which interface the packet uses to exit the router.
When no specific interface is configured, a wildcard interface address of 0.0.0.0 (for IPv4) or :: (for IPv6) is used, and the IP socket selects the best outbound interface.
Examples
In the following example, the user specifies that the IP address of Ethernet interface 0 is the source IP address for all syslog messages:
Router(config)# logging source-interface ethernet 0The following example specifies that the IP address for Ethernet interface 2/1 is the source IP address for all syslog messages:
Router(config)# logging source-interface ethernet 2/1The following sample output displays that the logging source-interface command is configured on a VRF source interface:
Router# show running interface loopback49Building configuration...Current configuration : 84 bytes!interface Loopback49ip vrf forwarding blackip address 49.0.0.1 255.0.0.0endRouter# show running | includes logginglogging source-interface Loopback49 vrf blacklogging host 130.0.0.1 vrf blackRelated Commands
logging event link-status (global configuration)
To change the default or set the link-status event messaging during system initialization, use the logging event link-status command in global configuration mode. To disable the link-status event messaging, use the no form of this command.
logging event link-status {default | boot}
no logging event link-status {default | boot}
Syntax Description
Defaults
Interface state-change messages are not sent.
Command Modes
Global configuration
Command History
Usage Guidelines
You do not have to enter the logging event link-status boot command to enable link-status messaging during system initialization. The logging event link-status default command logs system messages even during system initialization.
If you enter both the logging event link-status default and the no logging event link-status boot commands, the interface state-change events are logged after all modules in the Catalyst 6500 series switch come online after system initialization. The logging event link-status default and the no logging event link-status boot commands are saved and retained in the running configuration of the system.
When both the logging event link-status default and the no logging event link-status boot commands are present in the running configuration and you want to display the interface state-change messages during system initialization, enter the logging event link-status boot command.
Examples
This example shows how to enable the system logging of the interface state-change events on all interfaces in the system:
Router(config)# logging event link-status defaultRouter(config)#This example shows how to enable the system logging of interface state-change events on all interfaces during system initialization:
Router(config)# logging event link-status bootRouter(config)#This example shows how to disable the system logging of interface state-change events on all interfaces:
Router(config)# no logging event link-status defaultRouter(config)#This example shows how to disable the system logging of interface state-change events during system initialization:
Router(config)# no logging event link-status bootRouter(config)#Related Commands
show running-config
Displays the status and configuration of the module or Layer 2 VLAN.
logging event link-status (interface configuration)
To enable link-status event messaging on an interface, use the logging event link-status command in interface configuration mode. To disable link-status event messaging, use the no form of this command.
logging event link-status [bchan | dchan | nfas]
no logging event link-status [bchan | dchan | nfas]
Syntax Description
Command Default
Interface state-change messages are not sent.
Command Modes
Interface configuration (config-if)
Command History
Usage Guidelines
To enable system logging of interface state-change events on a specific interface, enter the logging event link-status command.
Examples
The following example shows how to enable link-status event messaging on an interface:
Router(config-if)# logging event link-statusThis example shows how to disable link-status event messaging on an interface:
Router(config-if)# no logging event link-statuslogging event subif-link-status
To enable the link-status event messaging on a subinterface, use the logging event subif-link-status command in interface configuration mode. To disable the link-status event messaging on a subinterface, use the no form of this command.
logging event subif-link-status
no logging event subif-link-status
Syntax Description
This command has no arguments or keywords.
Defaults
Subinterface state-change messages are not sent.
Command Modes
Interface configuration
Command History
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.
Usage Guidelines
This command is not supported on Cisco 7600 series routers that are configured with a Supervisor Engine 720.
To enable system logging of interface state-change events on a specific subinterface, enter the logging event subif-link-status command.
To enable system logging of interface state-change events on a specific interface, enter the logging event link-status command.
To enable system logging of interface state-change events on all interfaces in the system, enter the logging event link-status command.
Examples
This example shows how to enable the system logging of the interface state-change events on a subinterface:
Router(config-if)# logging event subif-link-statusRouter(config-if)#This example shows how to disable the system logging of the interface state-change events on a subinterface:
Router(config-if)# no logging event subif-link-statusRouter(config-if)#Related Commands
show running-config
Displays the status and configuration of the module or Layer 2 VLAN.
logging-events
To print typical T3 controller Up and Down messages on a Channelized T3 Port Adapter, use the logging-events command in T3 controller configuration mode. Use the no form of this command to disable printing of the T3 controller Up and Down messages.
logging-events [detail]
[no] logging-events
Syntax Description
detail
(Optional) Enables printing the reason code when a T3 controller changes from the Up to Down state.
Defaults
The logging-events command is the default.
Command Modes
T3 controller configuration
Command History
Usage Guidelines
When the no logging-events command disables printing of the T3 controller Up and Down messages, these messages will neither appear on the console nor in the logs.
Examples
The following example uses the logging-events [detail] command to show the Out-of-Frame (OOF) reason code when the T3 controller changes from an Up state to a Down state:
Router(config-controller)# logging-events detail*Jun 19 17:47:50: %CONTROLLER-5-DOWNDETAIL: Controller T3 4/1, changed state to down due to OOFRelated Commands
t1 logging-events
Prints the typical T1 controller Up and Down messages on a channelized T3 port adapter.
logging-events (T1-E1 controller)
To show the controller state change and alarms on a controller, use the logging-events command in controller configuration mode. To turn off controller state change reporting, use the no form of the command.
logging-events detail
no logging-events
Syntax Description
Defaults
Logging-events is the default.
Command Modes
Controller configuration
Command History
Usage Guidelines
Use the logging-events command to show the state change and alarms on a controller on an 8-Port Channelized T1/E1 Serial SPA.
Examples
The following shows enabling the logging-events command.
Router(config)#contr e1 2/1/0Router(config-controller)# logging-eventsRelated Commands
controller
Configures a T1, E1, or T3 controller and enters controller configuration mode.
show controller
Displays controller configuration.
loopback (CEM)
To set the loopback method for testing a T1, E1, or serial CEM interface, use the loopback command in controller configuration or CEM configuration mode. To remove any existing loopback, use the no form of this command.
Cisco NM-CEM-4SER
loopback {local | network}
no loopback
Cisco NM-CEM-4TE1
loopback {local {payload | line} | network}
no loopback
Syntax Description
Command Default
No loopback is configured for a CEM interface.
Command Modes
Cisco NM-CEM-4SER
CEM configuration
Cisco NM-CEM-4TE1
Controller configuration
Command History
Usage Guidelines
Use this command to create a loopback for a CEM interface. You can use a loopback to test for equipment malfunction caused by the interface.
The NM-CEM-4TE1 does not respond to loopback requests initiated by the CPE, locally attached or remote, using the extended super frame (ESF) Facility Data Link (FDL) mechanism or by any other mechanism.
The NM-CEM-4SER does not respond to any form of loopback request initiated by the locally attached or remote CPE on the Local Loop (LL) or Remote Loop (RL) control leads. Nor does the NM-CEM-4SER respond to any form of loopback request initiated by the locally attached or remote CPE using in-band loopback codes.
Examples
The following example shows how to create a loopback on a CEM T1/E1 interface so that data received from a remote CPE is transmitted back to the remote CPE on the network.
Router(config-controller)# loopback networkThe following example shows how to create a loopback of data in individual time slots on a CEM T1/E1 interface. Data received from a locally attached CPE will be sent back to the locally attached CPE.
Router(config-controller)# loopback local payloadThe following example shows how to create a loopback on a serial CEM channel so that data received from a remote CPE is transmitted back to the remote CPE on the network.
Router(config-cem)# loopback networkRelated Commands
cem
Enters circuit emulation configuration mode.
controller
Enters controller configuration mode.
loopback (DSL controller)
To test the controller and configure the core loopback, use the loopback (DSL Controller) command in controller configuration mode. To remove the loopback interface, use the no form of this command.
loopback {analog | digital}
no loopback
Syntax Description
analog
Loops the circuit at the analog hybrid to verify the analog loopback hardware to the analog hybrid.
digital
Loops the circuit at the framer to verify the hardware to the framer.
Defaults
No default behavior or values.
Command Modes
Controller configuration
Command History
Usage Guidelines
Analog and digital loopbacks are local loopbacks. Digital loopbacks loop the circuit at the framer to verify the hardware to the framer, and analog loopbacks loop the circuit at the analog hybrid to verify the analog loopback hardware to the analog hybrid. The controller must be shut down before loopback can be configured.
Examples
If the controller is still up, the router will prompt you to turn the controller off as shown in this example:
Router(config-controller)# loopback analogPlease shut down the xDSL controllerRouter(config-controller)# loopback digitalPlease shut down the xDSL controllerThe following example shows the configuration of a loopback digital interface:
Router(config-controller)# loopback digitalPlease shut down the xDSL controllerRouter(config-controller)# shutdownRouter(config-controller)#00:59:50: %CONTROLLER-5-UPDOWN: Controller DSL 0/0, changed state toadministratively downRouter(config-controller)#Router(config-controller)# loopback digitalRouter(config-controller)# no shutdownApr 23 06:59:01.435: DSL 0/0 controller Link up! line rate: 4608 Kbpso00:59:59: %CONTROLLER-5-UPDOWN: Controller DSL 0/0, changed state to upRouter(config-controller)#endRouter# show controllers dsl 0/0DSL 0/0 controller UPLocal Digital loopback is runningGlobespan xDSL controller chipsetDSL mode: SHDSL Annex BFrame mode: UtopiaConfigured Line rate: 4608KbpsLine Re-activated 4 times after system bootupLOSW Defect alarm: ACTIVECRC per second alarm: ACTIVELine termination: COFPGA Revision: 0xA7Line 0 statisticsCurrent 15 min CRC: 679Current 15 min LOSW Defect: 8Current 15 min ES: 5Current 15 min SES: 5Current 15 min UAS: 397Previous 15 min CRC: 0Previous 15 min LOSW Defect: 0Previous 15 min ES: 0Previous 15 min SES: 0Previous 15 min UAS: 0Line 1 statisticsCurrent 15 min CRC: 577Current 15 min LOSW Defect: 8Current 15 min ES: 7Current 15 min SES: 4Current 15 min UAS: 411Previous 15 min CRC: 0Previous 15 min LOSW Defect: 0Previous 15 min ES: 0Previous 15 min SES: 0Previous 15 min UAS: 0Line-0 statusChipset Version: 1Firmware Version: A29733Modem Status: un checked mode, Status 83Last Fail Mode: No Failure status:0x0Line rate: 2312 KbpsFramer Sync Status: In SyncRcv Clock Status: In the RangeLoop Attenuation: 0.0 dBTransmit Power: 13.5 dBReceiver Gain: 936.8420 dBSNR Sampling: 16.960 dBLine-1 statusChipset Version: 1Firmware Version: A29733Modem Status: un checked mode, Status 83Last Fail Mode: No Failure status:0x0Line rate: 2312 KbpsFramer Sync Status: In SyncRcv Clock Status: In the RangeLoop Attenuation: 0.0 dBTransmit Power: 13.5 dBReceiver Gain: 936.8420 dBSNR Sampling: 16.3590 dBDying Gasp: PresentRelated Commands
loopback (E3 controller)
To loop an entire E3 line toward the line and back toward the router, use the loopback command in controller configuration mode. To remove the loop, use the no form of this command.
loopback {local | network {line | payload}}
no loopback
Syntax Description
Defaults
local
Command Modes
Controller configuration
Command History
Usage Guidelines
Use this command for troubleshooting purposes. To verify that a loopback is configured on the interface, use the show controllers e3 EXEC command. Note that line loopback is available only in C-bit parity mode.
Examples
The following example shows how to configure the controller located in slot 1, port 0 for a local loopback:
Router(config)# controller e3 1/0Router(config-controller)# loopback localRelated Commands
loopback (interface)
To diagnose equipment malfunctions between the interface and device, use the loopback command in interface configuration mode. To disable the test, use the no form of this command.
loopback
no loopback
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
Loopback on HSSI Cards
On High-Speed Serial Interface (HSSI) cards, the loopback function configures a two-way internal and external loop on the HSA applique of the specific interface.
Loopback on MCI and SCI Serial Interface Cards
On MCI and SCI serial interface cards, the loopback functions when a CSU/DSU or equivalent device is attached to the router or access server. The loopback command loops the packets through the CSU/DSU to configure a CSU loop, when the device supports this feature.
Loopback on MCI and MEC Ethernet Cards
On the MCI and MEC Ethernet cards, the interface receives back every packet it sends when the loopback command is enabled. Loopback operation has the additional effect of disconnecting network server functionality from the network.
Loopback on CSC-FCI FDDI Cards
On the CSC-FCI FDDI card, the interface receives back every packet it sends when the loopback command is enabled. Loopback operation has the additional effect of disconnecting network server functionality from the network.
Loopback on Token Ring Interface Cards
On all Token Ring interface cards (except the 4-megabit CSC-R card), the interface receives back every packet it sends when the loopback command is enabled. Loopback operation has the additional effect of disconnecting network server functionality from the network.
Active Loopback Interfaces
To show interfaces currently in loopback operation, use the show interfaces loopback EXEC command.
Note
Examples
The following example configures the loopback test on Ethernet interface 4:
Router(config)# interface ethernet 4Router(config-if)# loopbackRelated Commands
down-when-looped
Configures an interface to inform the system it is down when loopback is detected.
show interfaces loopback
Displays information about the loopback interface.
loopback (J1 controller )
To set the loopback method for testing the J1 interface, use the loopback command in controller configuration mode. To turn off loopback, use the no form of this command. This command should be used for testing purposes only.
loopback {local | line | isolation}
no loopback {local | line | isolation}
Syntax Description
local
Places the interface into local loopback mode.
line
Places the interface into external loopback mode at the line level.
isolation
Places the interface into both local and line loopback mode.
Defaults
No loopback is configured.
Command Modes
Controller configuration
Command History
Examples
The following example establishes a loopback of the incoming J1 signal on controller J1 3/0:
Router(config)# controller j1 3/0Router(config-controller)# loopback lineloopback (PA-MC-8TE1+ port adapter)
To enable loopback testing of data for the PA-MC-8TE1+ port adapter, use the loopback command in interface configuration mode. To disable loopback testing, use the no form of this command.
loopback [internal | line]
no loopback [internal | line]
Syntax Description
Defaults
Loopback mode is not enabled.
Command Modes
Interface configuration
Command History
Examples
In the following example, a loopback is set for the PA-MC-8TE1+ port adapter in slot 2:
Router(config)# interface 2/0Router(config-if)# loopback line
