Catalyst 3550 Vlan tagging on subinterface

by karan on June 15, 2010

I tried to encapsulate a subinterface on a Layer 3 interface ( no switchport ) on Catalyst 3550 but there was no option for encapsulation dot1q <vlan number> command?

When I try to add a IP address on that subinterface it notifies me that :

Configuring IP routing on a LAN subinterface is only allowed if that

subinterface is already configured as part of an IEEE 802.10, IEEE 802.1Q, or ISL vLAN.

just like on routers, but no such command, so my question is if there is any other command equal to that, or there isn’t such feature in this catalyst serie or should I change the IOS?

IOS version 3550-i5q3l2-mz.121-22.EA2.bin

{ 3 comments… read them below or add one }

arul June 15, 2010 at 4:18 am

A routed port is a physical port that acts like a port on a router; it does not have to be connected to a router. A routed port is not associated with a particular VLAN, as is an access port. A routed port behaves like a regular router interface, except that it does not support VLAN subinterfaces. Routed ports can be configured with a Layer 3 routing protocol.
This is from 3550 configuration guide.
You can trunk that port and then create multiple vlans and accomplish the same thing.

Kumar June 15, 2010 at 4:18 am

thanks for response

It seems that I have to configure a port as Layer 2.

arul June 15, 2010 at 4:19 am

You cannot configure sub-interfaces on 3550 or most catalyst switches on ethernet interfaces.

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