• View

Evil_TTL> show | s

L2TPv3

Category:Cisco Systems -> Routing and Switching

This is how to connect two branch offices over the Internet with Layer 2 support allowing broadcasts and VLAN tags. The first obvious choice is to try MPLS. But if MPLS is not supported then L2TPv3 will come into play. L2TPv3 connection is established between two routers which have the access to the interesting VLAN. In our case it is VLAN100.

HQ Configuration	Branch office config
l2tp-class L2TP.Class   digest secret 0 cisco hash SHA1   pseudowire-class PWClass   encapsulation l2tpv3   ip local interface FastEthernet0/1   interface FastEthernet0/0.100  encapsulation dot1Q 100  xconnect 203.0.113.15 1000 pw-class PWClass   interface FastEthernet0/1  ip address 198.51.100.23 255.255.255.0	l2tp-class L2TP.Class   digest secret 0 cisco hash SHA1   pseudowire-class PWCLass  encapsulation l2tpv3   ip local interface FastEthernet0/1   interface FastEthernet0/0.100   encapsulation dot1Q 100   xconnect 198.51.100.23 1000 pw-class PWCLass   interface FastEthernet0/1   ip address 203.0.113.15 255.255.255.0

L2TPv3 is used to form pseudowire. All packets arriving to interface FastEthernet0/0.100 of any router are forwarded to L2TPv3 tunnel with L2 headers.

CEF must be turned on. Also, if you need to use different VLAN numbers on both ends, then you can use VLAN ID Rewrite feature

Troubleshooting: By privilege15