Changing MTU size

[adnan]

Hi, All.

I am trying to change the regular MTU value on a vlan interface. This is how the setup looks like. RSM running IOS ver 12.2(6a) in slot 4 on a catalyst 5500 switch. There is a vlan interface on RSM where I can sucessfully increase the tag-switching mtu , while changing the regular MTU size from 1522 to 1544 I get the following message

(config-if)#mtu 1544

% Interface Vlanxx does not support user settable mtu.

(config-if)#ip mtu 1544

% Invalid IP MTU specified; minimum 68, maximum 1500

(config-if)#ip mtu ?

<68-1000000> MTU (bytes).

I am having no luck in changing the MTU size with above commands. Can anyone help or shed some more light on chainging the regular MTU size.

Thanks,

Adnan

[thisisshanky]

Try changing or setting the mtu for a particular vlan using the command,

set vlan mtu from the switch prompt for the vlan.

[adnan]

Thanks for you reply, the regular MTU vlaue that I am trying to change is for an interface that is on an RSM ( Route switch module )sitting on 5500.