6500 Portchannel Allowed VLANs Trunk

Answered Question
Oct 26th, 2009
User Badges:

I am having a problem getting allowed trunks to show up in my configuration


I am setting up the portchannels on the 6513 to trunk. I have them set for encap dot1q, switchport, and switchport mode trunk.


When I go to add the switchport trunk allowed vlan add 2,100,110... it doesnt get added.


When I issue the show interface port-channel 6 trunk it shows that no vlans are allowed?


Probably an easy question that I am just missing.


The port channel is shut down but is not yet connected to the other switch so it is admin up protocol down.

Thanks


James

Correct Answer by glen.grant about 7 years 5 months ago

You could try removing all vlans but those 3 and see what happens

switchport trunk allowed vlan remove 1,3-99,101-109,111-1025 etc...

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (1 ratings)
Loading.
abbey1234 Mon, 10/26/2009 - 15:09
User Badges:

possible example of syntax:


Port-channel64

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 123, 124, 125

switchport mode trunk

switchport nonegotiate

no ip address

jfraasch Tue, 10/27/2009 - 05:30
User Badges:

That's exactly the command set I used. Didnt show up in the running config.

abbey1234 Tue, 10/27/2009 - 07:32
User Badges:

Thanks for the feedback. Perhaps if you provide us a copy of your running config we can see something missing... i.e. port shutdown or no vlan in vtp domain database.......

jason.henderson Mon, 10/26/2009 - 15:26
User Badges:

Have you tried allowing the vlans on the interfaces that belong to the port-channel? Make sure they're all the same config.

jfraasch Tue, 10/27/2009 - 05:32
User Badges:

Shouldn't have to do that really. That's kind of the purpose of the portchannel in the first place. I will have about 16 different port channels on each 6513. Largest portchannel will be 4 ports. I'd prefer to just configure the portchannel with the VLANs as opposed to all the physical ports.

Correct Answer
glen.grant Mon, 10/26/2009 - 15:57
User Badges:
  • Purple, 4500 points or more

You could try removing all vlans but those 3 and see what happens

switchport trunk allowed vlan remove 1,3-99,101-109,111-1025 etc...

jfraasch Tue, 10/27/2009 - 05:33
User Badges:

Interesting thought. Will give it a shot. But right now it says I have NONE allowed. Maybe a little reverse psychology will do the switch good!

jfraasch Tue, 10/27/2009 - 09:09
User Badges:

Glen you were definitely on the right track. I brought up the other side of the portchannel so I could troubleshoot.


What it ended up being is that on CoreA I had VLANs 1-4094 allowed and on CoreB I had only the VLANs I wanted to allow in the config.


I remembered that some point in the early troubleshooting of this issue that I put the switchport trunk allowed VLAN add all command. Unfortunately for Cisco users, this actual command does not show up in the running config.


I ended up doing a switchport trunk allowed vlan none command then issued the switchport trunk allowed vlan 2,100,110 and now only those correct VLANs are on the trunk.


Thanks for everyone's help. Now I am off to configure the HA for the FWSM on the two Chassis. I am sure you will hear from me again soon.


Five stars to Glen! Thanks.


James

Actions

This Discussion