Problem with VLAN on Catalyst 3500XL

[d.eberwein]

Hello,

i have a little problem with my switch. This is my Config for port 22:

interface FastEthernet0/22

duplex full

speed 100

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 1,2,5,6,

switchport mode trunk

How can i remove the VLAN 1(default) from this trunk? Is this possible to remove the default VLAN1?

Thanks

[ankurbhasin]

Hi Friend,

No you cannot remove deault vlan 1 from trunk port on 3500Xl switch though you ca do this on some high end switches like cat6k switch.

switchport trunk allowed vlan remove vlan-list

Define the VLANs that are not allowed to send and receive on the port.

The vlan-list parameter is a range of VLAN IDs Separate nonconsecutive VLAN IDs with a comma and no spaces; use a hyphen to designate a range of IDs. Valid IDs are from 2 to 1001.

http://www.cisco.com/univercd/cc/td/doc/product/lan/c2900xl/29_35wc4/sc/swvlan.htm#xtocid44

HTH, if yes please rate the post.

Ankur

[d.eberwein]

Thank you for your fast answer.

Can you say to me, why i can't remove default vlan 1?

In this Trunk, are there vlan1-tagged packets?

It is interresting to know why this isn't possible.

[ankurbhasin · Accepted solution]

HI Friend,

Cisco designed VLAN 1 to carry management traffic like CDP, VTP etc etc and that is the reason in old and low end switches this feature was not introduced.

By default in dot1q trunk vlan 1 goes as native vlan which means not tagged

What you can do is just do not assign any ports to vlan 1.

HTH, if yes please rate the post.

Ankur

[glen.grant]

I would check your syntax when your are trying to remove , you should be able to remove vlan 1 from the allowed links . We have many trunked links on IOS switches where vlan 1 is not allowed . Enter "switchport trunk allowed vlan remove 1" . Kind of a convoluted command but that is cisco code for you.

[ankurbhasin]

Hi Glen,

Can you confirm the IOS switches which you have where you have restricted vlan 1 from trunk are XL switches?

AFAIK XL switches cannot restrict vlan 1 from trunk but you can restrict vlan 1 from trunk on 2950 and 3550s and big daddy like cat6k.

Regards,

Ankur

[glen.grant]

My bad didn't see they were the old XL's , I was looking at current 2950,4500's etc... We don't have any 3500's . Sorry for the confusion.