allows you to configure your network to detect a failure in the network and
reroute the Layer 2 service to another endpoint that can continue to provide
service. This feature provides the ability to recover from a failure of either
the remote provider edge (PE) router or the link between the PE and customer
edge (CE) routers.
L2VPNs can provide
pseudowire resiliency through their routing protocols. When connectivity
between end-to-end PE routers fails, an alternative path to the directed LDP
session and the user data takes over. However, there are some parts of the
network in which this rerouting mechanism does not protect against
interruptions in service.
enables you to set up backup pseudowires. You can configure the network with
redundant pseudowires and redundant network elements.
Prior to the failure
of the primary pseudowire, the ability to switch traffic to the backup
pseudowire is used to handle a planned pseudowire outage, such as router
describes the configuration for pseudowire redundancy.
/* Configure a cross-connect group with a static point-to-point
cross connect */
Router(config-l2vpn)# xconnect group A
Router(config-l2vpn-xc)# p2p xc1
ROuter(config-l2vpn-xc-p2p)# interface tengige 0/0/0/0.2
Router(config-l2vpn-xc-p2p)# neighbor 10.1.1.2 pw-id 2
/*Configure the pseudowire segment for the cross-connect group */
/*Configure the backup pseudowire segment for the cross-connect group */
Router(config-l2vpn-xc-p2p-pw)# backup neighbor 10.2.2.2 pw-id 5
/*Commit your configuration */
Uncommitted changes found, commit them before exiting(yes/no/cancel)?
Router# show-running configuration
xconnect group A
interface tengige 0/0/0/0.2
neighbor ipv4 10.1.1.2 pw-id 2
backup neighbor 10.2.2.2 pw-id 5