VLAN extend L2TPV3

[Anukalp S]

Hi.. is it possible to extend vlan between two sites using L2TP. If yes, please suggest on below query.

> what types of licenses required on router to setup L2TP.

> Does vlan segment has be configured on router which need to extend on other site. OR if vlan exist behind router on L3 switch, will it work.

> Can L2TP be setup over internet and point to point circuit.

Please suggest.

[Philip D'Ath]

Correct,

Gig0/1

becomes a layer 2 port, and should have no layer 3 configuration on it.

You should not used the

encapsulation dot1q ..

command.  The switch, like a long patch lead, will simply forward every frame it receives.  Weather you want to use tags or not is controlled by the switch port you plug

Gig0/1

into.  Remember, just think of this as a long patch lead.  Frame in, frame out.  It doesn't care what is int he frames.

So the config should only be:

interface GigabitEthernet0/1
  xconnect 10.255.255.1 1 encapsulation l2tpv3 pw-class pw-site-to-site

[Anukalp S]

Thanks much again Philip.. could you brief me about connectivity on other side.

Suppose other side router has

G0/1 interface

which is connected to switch port, does this switch port also need to be in access vlan 100.

[Philip D'Ath · Accepted solution]

How would you configure the two switch ports if they were connected together using a patch lead?

Same answer when using L2TP.

[Anukalp S]

Thanks for your help..Philip.

[michalis1234]

Hi Philip,

I am trying to setup almost the same topology for a primary - dr topology.

For one vlan it works fine, for both access - trunk port configuration on the switches.

if I try to use more that one vlan, for example i need to extend 5 vlans on my dr site, it does not work. Is there any configuration example that could help me.

Shall I use

dot1q tags

on the routers ?

[Philip D'Ath]

Negative to the router.  It will transport any

dot1q tag

you present it.  Just make sure both switches at both sites are using trunking have have the same VLANs created, configured and allowed.

[michalis1234]

I have managed to resolve the issue.

The problem was not on the configuration but on the compatibility of my ASRs to old 3560 fastethernet switches on my lab. When I connected 3850 switches the L2tpv3 was up and running.

:)

Is there any reason why ASR routers do not support fastethernet port connectivity ?

I mean in case of a failure scenario there migth be a need to connect an older switch if you do not have any gigabit switch available.

:(

[Philip D'Ath]

This is bring back memories from decades ago.

I'm not sure the 3560's defaulted to using

802.1q

for trunking.  I think they might have used the really old Cisco proprietary trunking.  I think you had to tell them to use

dot1q

trunking.

[Philip D'Ath]

I remember now, it was called ISL.