Cisco Systems A9014CFD Configuring L2VPN Pseudowire Redundancy, Selects an E1 or T1 controller

Chapter 21 Configuring Pseudowire

Configuring L2VPN Pseudowire Redundancy

Configuring L2VPN Pseudowire Redundancy

The Cisco ASR 901 router supports the L2VPN pseudowire redundancy feature that provides backup service for circuit emulation (CEM) pseudowires. This feature enables the network to detect a failure, and reroute the Layer 2 (L2) service to another endpoint that can continue to provide the service. This feature also provides the ability to recover from a failure: either the failure of the remote PE router, or of the link between the PE and the CE routers.

Configure pseudowire redundancy by configuring two pseudowires for the CEM interface: a primary pseudowire and a backup (standby) pseudowire. If the primary pseudowire goes down, the router uses the backup pseudowire in its place. When the primary pseudowire comes back up, the backup pseudowire is brought down and the router resumes using the primary.

Figure 21-2shows an example of pseudowire redundancy.

Figure 21-2	Pseudowire Redundancy
		Primary
		pseudowire
		Redundant
CE1	PE1	PE2 attachment CE2
		circuits
		Backup
		pseudowire

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Note You must configure the backup pseudowire to connect to a different router than the primary pseudowire.

Complete the following steps to configure pseudowire redundancy on a CEM interface.

	Command		Purpose
Step 1	enable		Enables privileged EXEC mode.
			• Enter your password if prompted.
	Example:
	Router> enable
Step 1	configure terminal		Enters global configuration mode.
	Example:
	Router# configure terminal
Step 2	controller {e1 t1} slot/port		Selects an E1 or T1 controller.
	Example:
	Router(config)# controller t1 0/1
Step 3	[number] cem-group group-number		Creates a CEM interface and assigns it a CEM group number.
	{unframed timeslots timeslot}
	Example:
	Router(config-controller)#
	cem-group 5 timeslots 30}
		Cisco ASR 901 Series Aggregation Services Router Software Configuration Guide
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