Cisco IOS Cookbook, 2nd Edition

Configuring MPLS over ATM

Problem

You want to run MPLS over an ATM network.

Solution

There are really two solutions to this problem, depending on the capabilities of your ATM switches. The first and conceptually simpler solution is to configure your ATM switch to just pass ATM cells, but not to interact with MPLS at the IP layer.

First we will configure the two PE routers to run MPLS over ATM. Note that for these configurations we show only the additional configuration required for the MPLS over ATM functionality. Please refer to Recipe 26.2 for the remainder of the configuration for MPLS PE functionality:

Router-PE1#configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Router-PE1(config)#ip cef
Router-PE1(config)#mpls ip
Router-PE1(config)#interface ATM1/0
Router-PE1(config-if)#no ip address
Router-PE1(config-if)#exit
Router-PE1(config)#interface ATM1/0.1 mpls
Router-PE1(config-if)#ip address 10.1.1.2 255.255.255.252
Router-PE1(config-if)#mpls ip
Router-PE1(config-if)#exit
Router-PE1(config)#end
Router-PE1#

The other PE router’s configuration is identical, except for the IP address:

Router-PE3#configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Router-PE3(config)#ip cef
Router-PE3(config)#mpls ip
Router-PE3(config)#interface ATM1/0
Router-PE3(config-if)#no ip address
Router-PE3(config-if)#exit
Router-PE3(config)#interface ATM1/0.1 mpls
Router-PE3(config-if)#ip address 10.1.1.1 255.255.255.252
Router-PE3(config-if)#mpls ip Router-PE3(config-if)# ...