Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Attention: The Community will be in read-only mode on 12/14/2017 from 12:00 am pacific to 11:30 am.

During this time you will only be able to see content. Other interactions such as posting, replying to questions, or marking content as helpful will be disabled for few hours.

We apologize for the inconvenience while we perform important updates to the Community.

HWIC-1GE-SFP "Switchport Trunk"

I am trying to configure a HWIC-1GE-SFP on a 2821 as a 802.1q trunk to connect to a 3508 switch.

If i try a show int gig x/x/x I get "gig x/x/x is not a switchable port"

I read the documentation that these modules do support dot1q VLAN's so what am I missing?

SW version is c2800nm-ipvoicek9-mz.124-16.bin

New Member

Re: HWIC-1GE-SFP "Switchport Trunk"

Are you trying to make this a trunk port and create sub-interfaces? If so try the no switchport command, then create your sub's.

Not sure if you can do this with the HWIC's though.

Re: HWIC-1GE-SFP "Switchport Trunk"

Is the gig interface configured as a router port (no switchport). Can you try configuring the command 'switchport' under the interface?

Re: HWIC-1GE-SFP "Switchport Trunk"

the switchport command is not listed if I use a "?"

Re: HWIC-1GE-SFP "Switchport Trunk"

It appears HWIC-1GE-SFP is purely a layer 3 (router) interface. That makes sense as it doesn't support the 'switchport' command and the 'show int' command reveals it's not a switchable port. Moreover the product documentation shows 802.1q trunking is supported on this card.

In that case you should configure 802.1q subinterfaces on the router. This feature is called router-on-a-stick. The router can route all inter-vlan traffic with this feature. Configure the port on the switch that's connected to the 2800's router interface as 802.1q trunk.

Here's a sample configuration.

int g0/1.1

encapsulation dot1q 1 --> where 1 is the vlan #

int g0/1.2

encapsulation dot1q 2



CreatePlease to create content