LACP EtherChannel Configuration

Jan 19 2009   5:49AM GMT

Cisco Etherchannel Overview and how it can be configured in Cisco Catalyst Switches – Series 7

Posted by: Yasir Irfan
Cisco, Cisco Systems, Cisco Tips, Etherchannel, Etherchannel configuration, Etherchannel restrictions, Switches, Switching, Layer 2 EtherChannel Configuration, LACP EtherChannel Configuration, LACP, Cisco 3560 Catalyst Switch

Here we go, I will continue the series of Etherchannel overview, in my last post related to Etherchannel I showed how to configure a Layer 2 Etherchannel using the Cisco’s proprietary a PAGP (port aggregation protocol) Protocol in Cisco Catalyst Switches.

Now it’s the time to proceed further and we will see how to configure a Layer 2 Etherchannel using the LACP Protocol (Link Aggregation Protocol) in Cisco Catalyst Switches.

Here is the scenario which we will follow

From the above diagram we have two Cisco 3560 Catalyst Switches named ITKESW01 and ITKESW02.

We will configure a Layer 2 Etherchannel between the Cisco 3560 Catalyst Switches  ITKESW01 and ITKESW02. The  Giga Ethernet ports 0/45, 0/46/,0/47 & 0/48 on a Cisco 3560 Catalyst Switches  ITKESW01 are trunk ports  and they are connected to Giga Ethernet ports 0/1,0/2,0/3 and 0/4 (also trunk ports in desirable mode) in Cisco 3560 Catalyst Switch  ITKESW02.

 

The configuration is as follows

 

Configuration in the Cisco 3560 Catalyst Switch  ITKESW01

 

First run the command “Show interfaces trunk

 

ITKESW01#sho interfaces trunk

 

Port        Mode             Encapsulation  Status        Native vlan

Gi0/45      desirable                n-isl         trunking            1

Gi0/46      desirable                n-isl         trunking            1

Gi0/47      desirable                n-isl         trunking            1

Gi0/48      desirable                n-isl         trunking            1

 

Port        Vlans allowed on trunk

Gi0/45        1-4094

Gi0/46        1-4094

Gi0/47        1-4094

Gi0/48        1-4094

 

Port        Vlans allowed and active in management domain

Gi0/45        1

Gi0/46        1

Gi0/47        1

Gi0/48        1

 

Port        Vlans in spanning tree forwarding state and not pruned

Gi0/45       1

Gi0/46       1

Gi0/47       1

Gi0/48       1

 

ITKESW01#

 

Second Step configure the Giga Ethernet ports 0/45 to 0/48 in the Etherchannel

 

ITKESW01#config t

ITKESW01(config)# interface range gigabitEthernet 0/45 – 48

ITKESW01(config-if-range)# channel-protocol lacp

 

Note: LACP protocol is configured to be used in this channel

 

ITKESW01 (config-if-range)# channel-group 1 mode active

Note: A logical port-channel interface is automatically created when ports are grouped into a channel group.

Configure the mode active to be used in LACP

Configuration in the Cisco 3560 Catalyst Switch  ITKESW02

 

ITKESW02#sho interfaces trunk

 

Port        Mode             Encapsulation  Status        Native vlan

Gi0/1      desirable            n-isl         trunking            1

Gi0/2      desirable            n-isl         trunking            1

Gi0/3      desirable            n-isl         trunking            1

Gi0/4      desirable            n-isl         trunking            1

 

 

Port        Vlans allowed on trunk

Gi0/1        1-4094

Gi0/2        1-4094

Gi0/3        1-4094

Gi0/4        1-4094

 

 

Port        Vlans allowed and active in management domain

Gi0/1        1

Gi0/2        1

Gi0/3        1

Gi0/4        1

 

 

Port        Vlans in spanning tree forwarding state and not pruned

Gi0/1       1

Gi0/2       1

Gi0/3       1

Gi0/4       1

 

ITKESW02#

 

Second Step configure the Giga Ethernet ports 0/1 to 0/4 in the Etherchannel

 

ITKESW02#config t

ITKESW02(config)# interface range gigabitEthernet 0/1 – 4

ITKESW02(config-if-range)#channel-protocol lacp

 

Note: LACP protocol is configured to be used in this channel

 

ITKESW02 (config-if-range)# channel-group 1 mode active

Note: A logical port-channel interface is automatically created when ports are grouped into a channel group.

Configure the mode active to be used in LACP

Now run show command to display the Etherchannel configurations on the Cisco 3560 Catalyst Switches  ITKESW01 and ITKESW02

ITKESW01#sho etherchannel 1 summary

Flags:  D - down        P - in port-channel

        I - stand-alone s - suspended

        H - Hot-standby (LACP only)

        R - Layer3      S - Layer2

        u - unsuitable for bundling

        U - in use      f - failed to allocate aggregator

        d - default port

 

Number of channel-groups in use: 1

Number of aggregators:           1

 

Group  Port-channel  Protocol    Ports

——+————-+———–+———————————————–

1      Po1(SD)          LACP      Gi0/45 (P)   Gi0/46 (P)  Gi0/47 (P)  Gi0/48 (P)  

ITKESW01#

 

ITKESW02#sho etherchannel 1 summary

Flags:  D - down        P - in port-channel

        I - stand-alone s - suspended

        H - Hot-standby (LACP only)

        R - Layer3      S - Layer2

        u - unsuitable for bundling

        U - in use      f - failed to allocate aggregator

        d - default port

 

Number of channel-groups in use: 1

Number of aggregators:           1

 

Group  Port-channel  Protocol    Ports

——+————-+———–+———————————————–

1      Po1(SD)          LACP     Gi0/1 (P)   Gi0/2 (P)  Gi0/3 (P)  Gi0/4 (P)  

ITKESW02#