Interaction Between LA and VLANs

Whenever you create a port channel, the channel is added as an untagged member port of the default VLAN 1. For other VLANs, you must explicitly configure the channel as a member port, or the channel must be dynamically learned through GVRP. The channel does not inherit the VLAN membership of its member ports. When a port is aggregated into a bundle, that port will not be visible to layer 2 applications like VLAN and STP. Only the port of the port channel is visible to layer 2 applications. When a port gets aggregated into a port channel port, the port is removed from the membership of the specific VLAN. Similarly, when a port is deaggregated from a port channel, the port is added as a member port of the default VLAN.

To demonstrate this behavior, perform these steps.

1. Review the VLANs that are configured in the switch.

   SEFOS# show vlan
    
   Vlan database
   -------------
   Vlan ID             : 1
   Member Ports        : Ex0/1, Ex0/2, Ex0/3, Ex0/4, Ex0/5, Ex0/6
                         Ex0/7, Ex0/8, Ex0/9, Ex0/10, Ex0/11, Ex0/12
                         Ex0/13, Ex0/14, Ex0/15, Ex0/16, Ex0/17, Ex0/18
                         Ex0/19, Ex0/20, Ex0/21, Ex0/22, Ex0/23, Ex0/24
   Untagged Ports      : Ex0/1, Ex0/2, Ex0/3, Ex0/4, Ex0/5, Ex0/6
                         Ex0/7, Ex0/8, Ex0/9, Ex0/10, Ex0/11, Ex0/12
                         Ex0/13, Ex0/14, Ex0/15, Ex0/16, Ex0/17, Ex0/18
                         Ex0/19, Ex0/20, Ex0/21, Ex0/22, Ex0/23, Ex0/24
   Forbidden Ports     : None
   Name                :
   Status              : Permanent
   ----------------------------------------------------
   Vlan ID             : 2
   Member Ports        : Ex0/1, Ex0/2, Ex0/3, Ex0/4, Ex0/5
   Untagged Ports      : Ex0/1, Ex0/2, Ex0/3, Ex0/4, Ex0/5
   Forbidden Ports     : None
   Name                :
   Status              : Permanent
   ----------------------------------------------------

2. Aggregate port 1 and port 2 into a bundle.

   SEFOS(config)# set port-channel enable
   SEFOS(config)# interface port-channel 1
   SEFOS(config-if)# no shutdown
   SEFOS(config-if)# exit
   SEFOS(config)# interface extreme-ethernet 0/1
   SEFOS(config-if)# channel-group 1 mode active
   SEFOS(config-if)# exit
   SEFOS(config)# interface extreme-ethernet 0/2
   SEFOS(config-if)# channel-group 1 mode active
   SEFOS(config-if)# exit

3. Review the VLAN configuration information.

   SEFOS# show vlan
    
   Vlan database
   -------------
   Vlan ID             : 1
   Member Ports        : Ex0/3, Ex0/4, Ex0/5, Ex0/6, Ex0/7, Ex0/8
                         Ex0/9, Ex0/10, Ex0/11, Ex0/12, Ex0/13, Ex0/14
                         Ex0/15, Ex0/16, Ex0/17, Ex0/18, Ex0/19, Ex0/20
                         Ex0/21, Ex0/22, Ex0/23, Ex0/24, po1
   Untagged Ports      : Ex0/3, Ex0/4, Ex0/5, Ex0/6, Ex0/7, Ex0/8
                         Ex0/9, Ex0/10, Ex0/11, Ex0/12, Ex0/13, Ex0/14
                         Ex0/15, Ex0/16, Ex0/17, Ex0/18, Ex0/19, Ex0/20
                         Ex0/21, Ex0/22, Ex0/23, Ex0/24, po1
   Forbidden Ports     : None
   Name                :
   Status              : Permanent
   ------------------------------------------
   Vlan ID             : 2
   Member Ports        : Ex0/3, Ex0/4, Ex0/5
   Untagged Ports      : Ex0/3, Ex0/4, Ex0/5
   Forbidden Ports     : None
   Name                :
   Status              : Permanent

   After you create a port channel, the member ports of bundle 1 and bundle 2 are removed from all of the VLANs. The port channel port becomes the member of the default VLAN.

4. Delete the port channel, and review the VLAN configuration information.

   SEFOS(config)# no interface port-channel 1
   SEFOS(config)# exit
   SEFOS# show vlan
    
   Vlan database
   -------------
   Vlan ID             : 2
   Member Ports        : Ex0/3, Ex0/4, Ex0/5
   Untagged Ports      : Ex0/3, Ex0/4, Ex0/5
   Forbidden Ports     : None
   Name                :
   Status              : Permanent
   ----------------------------------------------------
   Vlan ID             : 1
   Member Ports        : Ex0/1, Ex0/2, Ex0/3, Ex0/4, Ex0/5, Ex0/6
                         Ex0/7, Ex0/8, Ex0/9, Ex0/10, Ex0/11, Ex0/12
                         Ex0/13, Ex0/14, Ex0/15, Ex0/16, Ex0/17, Ex0/18
                         Ex0/19, Ex0/20, Ex0/21, Ex0/22, Ex0/23, Ex0/24
   Untagged Ports      : Ex0/1, Ex0/2, Ex0/3, Ex0/4, Ex0/5, Ex0/6
                         Ex0/7, Ex0/8, Ex0/9, Ex0/10, Ex0/11, Ex0/12
                         Ex0/13, Ex0/14, Ex0/15, Ex0/16, Ex0/17, Ex0/18
                         Ex0/19, Ex0/20, Ex0/21, Ex0/22, Ex0/23, Ex0/24
   Forbidden Ports     : None
   Name                :
   Status              : Permanent

   After you delete the port channel, note the port channel port is removed from the VLAN. Member ports of bundles 1 and bundle 2 become members of the default VLAN, but not of other VLANs.