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Bronze

adding a VLAN to a trunk without the trunk going down

I am working on two 6509 and few 4848...I just added a VLAN to my VLAN database and would like to allow it on few trunks without them going down. Last time I did, the trunks went down.

Thanks

1 ACCEPTED SOLUTION

Accepted Solutions

Re: adding a VLAN to a trunk without the trunk going down

All you have to do is to add the following command

switchport trunk allowed vlan add

The trunk should not go down due to this

Note that if you leave out the "add" modifier you will remove all the currently configured VLANs from the trunk. This will almost certainly take the switch off the net and prevent you from communicating with it.

HTH, rate if it does

Narayan

5 REPLIES
Hall of Fame Super Bronze

Re: adding a VLAN to a trunk without the trunk going down

Adding a Vlan to a database shouldn't cause the trunks to go down unless you are doing manual pruning. Is that the case here ?

Re: adding a VLAN to a trunk without the trunk going down

All you have to do is to add the following command

switchport trunk allowed vlan add

The trunk should not go down due to this

Note that if you leave out the "add" modifier you will remove all the currently configured VLANs from the trunk. This will almost certainly take the switch off the net and prevent you from communicating with it.

HTH, rate if it does

Narayan

Bronze

Re: adding a VLAN to a trunk without the trunk going down

I should of mentioned that the trunks are part of etherchannel. Would that make a difference? I have for intstance 8 interfaces that are member of an etherchannel.

Re: adding a VLAN to a trunk without the trunk going down

I dont think that etherchannel should make a difference and trunk should not go down

Narayan

Hall of Fame Super Bronze

Re: adding a VLAN to a trunk without the trunk going down

No difference whatsoever, just use the range command so all ports take the changes at the same time.

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