I've got a ten gig interface on a 6509 running 12.2(33) configured as a trunk, but I've not been able to add any allowed VLANs as I've done before on other ten gig ports on different 6509 chassis. Am I missing something obvious?
I'm assuming that the reason I'm unable to set the encapsulation to dot1q is because the new hardware doens't support ISL, hence no need. The command to add the VLANs however doesn't get rejected, it just doesn't appear to do anything.
I've tried adding single VLANs and multiples, but no joy. Any ideas?
Here's what I've done:
SWITCH_1631(config)#default int t4/1 Interface TenGigabitEthernet4/1 set to default configuration
SWITCH_1631#sh ru int t4/12 Building configuration... Current configuration : 65 bytes ! interface TenGigabitEthernet4/12 no ip address shutdown end
SWITCH_1631(config)#int t4/1 SWITCH_1631(config-if)#switchport SWITCH_1631(config-if)#switchport mode trunk SWITCH_1631(config-if)#switchport trunk allowed vlan ? WORD VLAN IDs of the allowed VLANs when this port is in trunking mode add add VLANs to the current list all all VLANs except all VLANs except the following none no VLANs remove remove VLANs from the current list SWITCH_1631(config-if)#switchport trunk allowed vlan add 700 SWITCH_1631(config-if)# SWITCH_1631#sh vlan id 700 VLAN Name Status Ports ---- -------------------------------- --------- ------------------------------- 700 VLAN_NAME active <snip>
SWITCH_1631#sh ru int t4/1 Building configuration... Current configuration : 74 bytes ! interface TenGigabitEthernet4/1 switchport switchport mode trunk end
The problem was that I've always been advised that best practise is to only allow the VLANs that are actually required on a trunk to avoid broadcasting traffic unnecessarily. I worked out what the issue was though, and it was a pretty simple one!
Once I saw that 1-4094 was allowed I tried "switchport trunk allowed vlan remove 700" which worked and left me with 1-699,701-4094.
Then I realised what the problem was trying to use the "add" command when all possible VLANs had already been added. As soon as I got rid of it and used "switchport trunk allowed vlan 700" followed by "switchport trunk allowed vlan add 701" I was back in business.
So it was a very simple issue, but thank you Steve for pointing me in the right direction and confirming that all the VLANs were already allowed!
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