- Preface
- EVC Command Reference
- MPLS Command Reference
- MPLS TP Command Reference
- Pseudowire Command Reference
- QoS Command Reference
- High Availability Command Reference
- REP Command Reference
- LAG and LACP Command Reference
- Span Command Reference
- MAC Learning Command Reference
- IGMP Snooping Command Reference
- MVR Command Reference
- Ethernet OAM, CFM, and Y.1731 Command Reference
- RMON Command Reference
- CDP Command Reference
- Miscellaneous Command Reference
- Index
Cisco CPT Command Reference Guide CTC and Documentation Release 9.5.x and Cisco IOS Release 15.2(01)
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- Updated:
- July 11, 2017
Chapter: LAG and LACP Command Reference
LAG and LACP Command Reference
This chapter describes commands to configure Link Aggregation Group (LAG) and Link Aggregation Control Protocol (LACP).
- channel-group
- interface port-channel
- lacp fast-switchover
- lacp max-bundle
- lacp min-bundle
- lacp port-priority
- lacp system-priority
- port-channel load-balance
- show interfaces port-channel
- show lacp
channel-group
To configure the interface in a channel group and set the Link Aggregation Control Protocol (LACP) mode, use the channel-group command in interface configuration mode. To remove the channel-group configuration from the interface, use the no form of this command.
Syntax Description
| channel-group-number | Integer that identifies the channel group. The range is from 1 to 128. |
| mode | Sets the LACP mode. |
| active | Enables LACP unconditionally. |
| passive | Enables LACP only when an LACP device is detected. This is the default state. |
Command Default
No channel groups are assigned.
Command Modes
Interface configuration (config-if)
Command History
| Release | Modification |
|---|---|
| 9.3.0 | This command was introduced. |
Usage Guidelines
You do not have to disable the IP address that is assigned to a physical interface that is part of a channel group, but we highly recommend in doing so. A port-channel must be created before member links are assigned to it.
Examples
The following example shows how to add the interface TenGigabitEthernet 4/1 to the channel group specified by port-channel 1:
Router(config)# interface port-channel 1 Router(config-if)# exit Router(config)# interface TenGigabitEthernet 4/1 Router(config-if)# channel-group 1
Related Commands
| Command | Description |
|---|---|
| interface port-channel | Creates a port-channel virtual interface. |
| lacp port-priority | Sets the LACP priority for a physical interface. |
| lacp system-priority | Sets the LACP priority for a system. |
| show interfaces port-channel | Displays traffic that is seen by a specific port channel. |
interface port-channel
To create a port-channel virtual interface, use the interface port-channel command in global configuration mode.
Syntax Description
| channel-number | Channel number assigned to this port-channel interface. |
Command Default
The port-channel virtual interface is not created.
Command Modes
Global configuration (config)
Command History
| Release | Modification |
|---|---|
| 9.3.0 | This command was introduced. |
Examples
The following example shows how to create a port-channel interface.
Router(config)# interface port-channel 2
Related Commands
| Command | Description |
|---|---|
| channel-group | Configures the interface in a channel group. |
| interface port-channel | Creates a port-channel virtual interface. |
| lacp min-bundle | Defines the minimum number of active bundled LACP ports allowed in a port channel. |
| lacp max-bundle | Defines the maximum number of active bundled LACP ports allowed in a port channel. |
| show interfaces port-channel | Displays traffic that is seen by a specific port channel. |
lacp fast-switchover
To enable 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
| Release | Modification |
|---|---|
| 9.3.0 | This command was introduced. |
Usage Guidelines
Before entering the lacp fast-switchover command, ensure the following:
- The port channel protocol type is LACP.
- The lacp max-bundle command has been entered on the port channel. The lacp fast-switchover command does not affect the lacp max-bundle command.
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 switch over, the port channel is also up.
Examples
The following example shows how to enable LACP 1:1 link redundancy:
Router(config-if)# lacp fast-switchover
Related Commands
| Command | Description |
|---|---|
| lacp max-bundle | Defines the maximum number of active bundled LACP ports allowed in a port channel. |
lacp max-bundle
To define the maximum number of active bundled 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-bundle-number
no lacp max-bundle
Syntax Description
| max-bundle-number | Maximum threshold of active member links allowed in the LACP bundle. The range from is 1 to 8. The maximum threshold value must be greater than or equal to the minimum threshold value. |
Command Default
A maximum number of active bundled LACP ports is not configured.
Command Modes
Interface configuration (config-if)
Command History
| Release | Modification |
|---|---|
| 9.3.0 | This command was introduced. |
Usage Guidelines
The value specified in the max-bundle-number argument determines the number of active links that are bundled in the port channel. The remaining links are in hot-standby mode.
Examples
The following example shows how to set three ports to bundle in port channel 2:
Router(config)# interface port-channel 2 Router(config-if)# lacp max-bundle 3
Related Commands
| Command | Description |
|---|---|
| interface port-channel | Creates a port-channel virtual interface. |
| lacp fast-switchover | Enables LACP 1:1 link redundancy. |
| lacp port-priority | Sets the LACP priority for a physical interface. |
| show interfaces port-channel | Displays traffic that is seen by a specific port channel. |
lacp min-bundle
To define the minimum number of active bundled LACP ports allowed in a port channel, use the lacp min-bundle command in interface configuration mode. To return to the default settings, use the no form of this command.
lacp min-bundle min-bundle-number
no lacp min-bundle
Syntax Description
| min-bundle-number | Minimum threshold of active member links allowed in the LACP bundle. The range is from 1 to 8. The default is 1. |
Command Default
A minimum number of active bundled LACP ports is not configured.
Command Modes
Interface configuration (config-if)
Command History
| Release | Modification |
|---|---|
| 9.3.0 | This command was introduced. |
Usage Guidelines
Use this command to configure the minimum number of active links allowed in an LACP bundle. When the number of active links falls below this minimum threshold, the port channel shuts down.
Examples
The following example shows how to set the minimum number of active links to five ports:
Router(config)# interface port-channel 2 Router(config-if)# lacp min-bundle 5
Related Commands
| Command | Description |
|---|---|
| interface port-channel | Creates a port-channel virtual interface. |
| show interfaces port-channel | Displays traffic that is seen by a specific port channel. |
lacp port-priority
To set the LACP 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 that indicates the priority for the physical interface. The range is from 0 to 65535. The default is 32768. |
Command Default
The default port priority is set to 32768.
Command Modes
Interface configuration (config-if)
Command History
| Release | Modification |
|---|---|
| 9.3.0 | This command was introduced. |
Usage Guidelines
You may assign a port priority to each port on a device running LACP. You can specify the port priority by using the lacp port-priority command or use the default port priority (32768). The port priority is used to decide which ports should be put in standby mode when a hardware limitation or the lacp max-bundle command configuration prevents all compatible ports from aggregating. Priority is supported only on port channels with LACP-enabled physical interfaces.
 Note |
A high priority number means a low priority. |
To verify the configured port priority, use the show lacp internal command.
Examples
The following example shows how to set a port priority of 23700 for an interface:
Router(config-if)# lacp port-priority 23700
Related Commands
| Command | Description |
|---|---|
| channel-group | Creates a channel group. |
| lacp max-bundle | Defines the maximum number of active bundled LACP ports allowed in a port channel. |
| lacp system-priority | Sets the LACP system priority. |
| show lacp | Displays information about LACP activity on the device. |
lacp system-priority
To set the LACP priority for a system, use the lacp system-priority command in global 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
| priority | Integer that indicates the LACP priority for the system. The range is from 0 to 65535. The default is 32768. |
Command Default
The default system priority is set to 32768.
Command Modes
Global configuration (config)
Command History
| Release | Modification |
|---|---|
| 9.3.0 | This command was introduced. |
Usage Guidelines
You can assign a system priority to each device running LACP. You can specify the system priority by using the lacp system-priority command or use the default system priority (32768). The system priority is used with the MAC address of the device to form the system ID and is used during negotiation with the other systems. The system priority is supported only on port channels with LACP-enabled physical interfaces.
Note |
A high priority number means a low priority. |
To verify the configured system priority, issue the show lacp command.
Examples
The following example shows how to set a system priority of 25500 for a device:
Router(config)# lacp system-priority 25500
Related Commands
| Command | Description |
|---|---|
| channel-group | Creates a channel group. |
| lacp port-priority | Sets the priority of a port. |
| show lacp | Displays information about LACP activity on the device. |
port-channel load-balance
To configure a member link for load balancing, use the port-channel load-balance command in interface configuration mode. To disable load balancing, use the no form of this command.
Syntax Description
| link link-id | Integer that identifies the member link for load balancing. The range is from 1 to 8. |
Command Default
The member link is not configured for load balancing.
Command Modes
Interface configuration (config-if)
Command History
| Release | Modification |
|---|---|
| 9.3.0 | This command was introduced. |
Usage Guidelines
The Cisco CPT supports manual load balancing and platform default load balancing. It does not support weighted load balancing in this release. When manual load balancing is not configured and applied to the service instance, the default platform load balancing mechanism is used.
Examples
The following example shows how to configure manual load balancing:
Router(config)# interface port-channel 1 Router(config-if)# port-channel load-balance link 1
show interfaces port-channel
To display the traffic on specific port channel, use the show interfaces port-channel command in privileged EXEC mode.
Syntax Description
| channel-number | (Optional) Port channel number. The range is 1 to 128. |
Command Modes
Privileged EXEC (#)
Command History
| Release | Modification |
|---|---|
| 9.3.0 | This command was introduced. |
Examples
The following is a sample output of the show interfaces port-channel command that shows how to view the information for a port channel interface.
Router# show interfaces port-channel 20
Port-channel20 is up, line protocol is up Hardware is GEChannel, address is 0002.0415.0002 (bia 0000.0000.0000) MTU 9600 bytes, BW 10000000 Kbit/sec, 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 : TenGigabitEthernet4/2 , Full-duplex, 10000Mb/s No. of passive members in this channel: 0 Last input never, output never, output hang never Last clearing of "show interface" counters never Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 37 packets input, 7820 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 39 packets output, 8088 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets 0 unknown protocol drops 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 Commands
| Command | Description |
|---|---|
| channel-group | Configures the interface in a channel group and sets the LACP mode. |
| interface port-channel | Creates a port-channel virtual interface. |
| lacp max-bundle | Defines the maximum number of active bundled LACP ports allowed in a port channel. |
| lacp min-bundle | Defines the minimum number of active bundled LACP ports allowed in a port channel. |
show lacp
To display LACP information, use the show lacp command in privileged EXEC mode.
Syntax Description
| channel-group-number | Number of the channel group. The range is from 1 to 128. |
| counters | Displays information about the LACP traffic statistics. |
| internal | Displays LACP internal information. |
| detail | (Optional) Displays detailed internal information. |
| neighbor | Displays information about the LACP neighbor. |
| sys-id | Displays the LACP system identification. It is a combination of the port priority and the MAC address of the device. |
Command Modes
Privileged EXEC (#)
Command History
| Release | Modification |
|---|---|
| 9.3.0 | This command was introduced. |
Usage Guidelines
Use the show lacp command to troubleshoot problems related to LACP in a network. If you do not specify a value for the argument channel-group-number, all the channel groups are displayed.
Examples
The following are sample outputs of the show lacp command that shows how to view the LACP activity in the network.
Router# 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 20
LACP port Admin Oper Port Port
Port Flags State Priority Key Key Number State
Te4/2 SA bndl 32768 0x5 0x5 0x42 0x3D
Router# show lacp 20 counters
LACPDUs Marker Marker Response LACPDUs
Port Sent Recv Sent Recv Sent Recv Pkts Err
---------------------------------------------------------------------
Channel group 20
Te4/2 21 18 0 0 0 0 0
Router# show lacp 20 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 20
LACP port Admin Oper Port Port
Port Flags State Priority Key Key Number State
Te4/2 SA bndl 32768 0x5 0x5 0x42 0x3D
Router# show lacp 20 counters
LACPDUs Marker Marker Response LACPDUs Port Sent Recv Sent Recv Sent Recv Pkts Err ------------------------------------------------------------------------------- Channel group: 20 Te4/2 26 31 0 0 0 0 0Router# show lacp sys-id
32768,0005.9b2e.18e0
Related Commands
| Command | Description |
|---|---|
| lacp port-priority | Sets the priority for the physical interfaces. |
| lacp system-priority | Sets the priority of the system. |
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