Unanswered Question
Nov 20th, 2008
User Badges:

I am interested in having a particular VLAN in two separate sites. I have read a little about it and was wondering if it would be possible to do across a point-to-point DS3 connection. I see a command on my serial link "Router2(config-if)#dot1q tunneling ethertype ?"

Will this command help me do what I want? I just want to be able to have a particular subnet in two different cities where it's not an option to split it.

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Jon Marshall Thu, 11/20/2008 - 07:01
User Badges:
  • Super Blue, 32500 points or more
  • Hall of Fame,

    Founding Member

  • Cisco Designated VIP,

    2017 LAN, WAN


If you want to extend a L2 vlan over a L3 routed link then L2TPv3 will allow you to do this -


You don't say what routers you are using or what IOS you have. L2TPv3 is not supported on all routers.


snickered Thu, 11/20/2008 - 07:51
User Badges:


Model: 7206VXR


Port Adapter: PA-2T3+=


Model: 7204VXR


Port Adapter: PA-2T3+=

Will this do? From what I can see "2-port T3 port adapter" will work (if that's what PA-2T3 is). And it looks like the 7200 series has been supported as of 12.0(21)S.

You wouldn't happen to have a base config for the interfaces, would you?

snickered Thu, 11/20/2008 - 08:18
User Badges:

The way I understand this is that you can't do this across a L3 link. Am I correct on this?

Giuseppe Larosa Thu, 11/20/2008 - 08:36
User Badges:
  • Super Silver, 17500 points or more
  • Hall of Fame,

    Founding Member

Hello Jason,

you are correct 802.1Q tunneling is a MAN feature provided by a L2 Service Provider, in your case L2TPv3 is the right tool as explained by Jon.

Hope to help



This Discussion