Solved: remove an interface from the channel group

emmawuxp06 · ‎02-01-2009

Hello,

There is a single connection between two 4500 switches.Switch A interface A - Switch B interface B

On switch A, the interface A is the only interface for an Etherchannel. On switch B, interface B does not belong to any Etherchannel.

The Etherchannel between the two switches is not formed.

My question is if I remove Interface A on switch A from the the Etherchannel, will it cause any issue, such as the interface down?

Thanks in advance.

Roberto Salazar · ‎02-01-2009

No, the interface should remain up/up but it will bounce as soon as you remove it from the channel-group. STP will probably reconverge, the port if trunking will try to form trunking.

c7609(config)#int g 4/24

c7609(config-if)#no channel-group 58 mode desirable

c7609(config-if)#

3w1d: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet4/24, changed state to down

3w1d: %LINEPROTO-5-UPDOWN: Line protocol on Interface Port-channel58, changed state to down

3w1d: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet4/24, changed state to up

3w1d: %LINK-3-UPDOWN: Interface Port-channel58, changed state to down

3w1d: %EC-SP-5-UNBUNDLE: Interface GigabitEthernet4/24 left the port-channel Port-channel58

3w1d: %LINEPROTO-SP-5-UPDOWN: Line protocol on Interface Port-channel58, changed state to down

3w1d: %LINK-SP-3-UPDOWN: Interface Port-channel58, changed state to down

c7609(config-if)#

c7609(config-if)#end

c7609#sh int

3w1d: %SYS-5-CONFIG_I: Configured from console by consoleg 4/24

GigabitEthernet4/24 is up, line protocol is up (connected)

View solution in original post

Roberto Salazar · ‎02-01-2009

No, the interface should remain up/up but it will bounce as soon as you remove it from the channel-group. STP will probably reconverge, the port if trunking will try to form trunking.

c7609(config)#int g 4/24

c7609(config-if)#no channel-group 58 mode desirable

c7609(config-if)#

3w1d: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet4/24, changed state to down

3w1d: %LINEPROTO-5-UPDOWN: Line protocol on Interface Port-channel58, changed state to down

3w1d: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet4/24, changed state to up

3w1d: %LINK-3-UPDOWN: Interface Port-channel58, changed state to down

3w1d: %EC-SP-5-UNBUNDLE: Interface GigabitEthernet4/24 left the port-channel Port-channel58

3w1d: %LINEPROTO-SP-5-UPDOWN: Line protocol on Interface Port-channel58, changed state to down

3w1d: %LINK-SP-3-UPDOWN: Interface Port-channel58, changed state to down

c7609(config-if)#

c7609(config-if)#end

c7609#sh int

3w1d: %SYS-5-CONFIG_I: Configured from console by consoleg 4/24

GigabitEthernet4/24 is up, line protocol is up (connected)

emmawuxp06 · ‎02-01-2009

Thanks for the quick response.

I can see from the log information, the line protocol of the interface is down after it was removed form the Etherchannel. But it bounced back immediately.

When the VLANs are added under the port-channel interface, they will automatically be added to the trunk port. Does this still apply to 4500? I will leave the way it is then and only operate the port-channel interface.

Thanks again.

Roberto Salazar · ‎02-01-2009

When the VLANs are added under the port-channel interface, they will automatically be added to the trunk port. Does this still apply to 4500? I will leave the way it is then and only operate the port-channel interface.

>> Do you mean that if you add a vlan on a trunking port-channel on 6509, and would this change done on 6509 happen on 4500 as well? No, the changes you made on a trunk port whether it's port-channel or the physical interface will NOT be applied to the neighboring device. The changes only happens on local device where the config was applied.

emmawuxp06 · ‎02-01-2009

Sorry I was not clear. I meant on the local switch, the VLANs added on the port-channel interface will be automatially added to the trunk interface.

Roberto Salazar · ‎02-01-2009

That's right.