switchport trunk pruning vlan except x

[dbass]

What is the purpose of the command?  I've been reading up and haven't been able to find anything that really describes it in depth.  The only way I can find to exclude a VLAN from being pruned is to use "swi tru pru vl add x-y"...or use the trusty old "swi tru all vl x-y" command of coarse.

In fact, I can't even get the command to be accepted and get an error - "Command rejected: Bad VLAN pruning list." when I try to put it in.

My platform's are 3560 and 3750...all new code.

[Edison Ortiz · Accepted solution]

The command tries to automatically prune the extended Vlans 1002-1005 as well as Vlan1.

Those Vlans can't be pruned so in addition to the Vlan you want to exclude, you also need to add Vlan 1 and 1002-1005 to the list.

SW1(config-if)#switchport trunk pruning vlan except 1,1002-1005

SW1(config-if)#do show run int f0/14
Building configuration...

Current configuration : 82 bytes
!
interface FastEthernet0/14
switchport trunk pruning vlan 2-1001,1006-4094
end

Regards,

Edison.

[dbass]

Thanks!

Odd that this command even exists...  When I put i in it actually just applies it as "swi tru pru vla x-y" (the inverse of what you type in the command).

[Edison Ortiz]

It provides a quick entry if you want to prune a lot of Vlans. You only need to add the ones you don't want pruning on.

But you are right, the syntax after the command is entered does not reflect the command itself.