[c-nsp] L2 Ethernet bridging over GRE issues

Roger Wiklund copse at xy.org
Fri Jan 28 07:39:08 EST 2011


> Do you have any nice sample config of back-to-back L2TP on Ethernet
> with and without VLANs.

Nevermind, I got it working. Sample config is someone else is interrested:

Router A:

pseudowire-class test
 encapsulation l2tpv3
 protocol none
 ip local interface Loopback0
!
interface Loopback0
 ip address 1.1.1.1 255.255.255.255
!
interface FastEthernet0/1
 description LAN
 no ip address
 speed 100
 full-duplex
 xconnect 2.2.2.2 1 encapsulation l2tpv3 manual pw-class test
  l2tp id 1 2


Router B:

pseudowire-class test
 encapsulation l2tpv3
 protocol none
 ip local interface Loopback0
!
interface Loopback0
 ip address 2.2.2.2 255.255.255.255
!interface FastEthernet0/1
 no ip address
 duplex auto
 speed auto
 xconnect 1.1.1.1 1 encapsulation l2tpv3 manual pw-class test
  l2tp id 2 1

Works like a charm. But only layer 2. As I cannot put an IP LAN
interface, no usable default gateway for HOST A and B.
It seems like you have to create 2 subinterfaces with the same VLAN
ID. And then put the IP on the first sub-if, and the xconnection on
the second subinterface without the IP, and then connected them to the
switch as a trunk.

/Roger


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