Removing AND deleting a vlan from a trunk

[Andy.S]

Hi All.

Im trying to accomplish the following, appreciate if you could confirm my action.

Scenario.

Swicth A -> Switch B -> Switch C

Vlans 10,20,30,40,50 are trunked from 'A' through 'B' to 'C'

I need to remove and delete vlan 30 from Switch B.

I intend to remove the vlan from the trunk ports on B, then remove the vlan.

Switch B 1/0/1 and 1/0/24 have the following:

switchport trunk allowed vlan 10,20,30,40

switchport trunk vlan add 50

I know the 'allowed' command has to be used with caution as this can easily remove the vlans. I know i could use:

switchport trunk vlan remove 30   but then this would appear in the running config and i want to REMOVE/DELETE 30 completely.

Would the command below be best?

switchport trunk allowed vlan 10,20,40,50

If i did this, what would happen to the line 'switchport trunk vlan add 50'  already there?

Also if switchport trunk vlan remove 30 was made, then the vlan deleted, would the line remain/error/disappear as the vlan would be deleted?

Thanks

Andy

[Iulian Vaideanu]

I've never seen a "switchport trunk allowed vlan remove X" line in a Cisco config...  ever - the effect of such a configuration command would be that vlan X would not show up in that interface's config anymore.

Your config should look the same after "switchport trunk allowed vlan remove 30" as it would after "switchport trunk allowed vlan 10,20,40,50", and the "switchport trunk vlan add 50" line will probably disappear (vlan 30 being removed from and vlan 50 being added to the line above).

[Andy.S]

Can the vlan just be deleted from the switch? or must it be removed from trunks first?

thanks

[Iulian Vaideanu]

It can (just be deleted from the switch), but only deleting it ("no vlan 30") won't make it disappear from the interface's config, which could cause confusion later...

[Zach Smith]

I agree with the below comments.  But yes you could accomplish this with either

'switch trunk allowed vlan remove 30' or 'switch trunk allowed vlan 10,20,40,50'

Then no vlan 30 on the switch