Cisco IOS Cookbook, 2nd Edition

Configuring ATM Subinterfaces

Problem

You want to configure an ATM link with PVCs that connect to several other routers.

Solution

Our preferred way of handling ATM PVCs is to use ATM subinterfaces. We also recommend using the IOS feature that sends ATM OAM cells periodically to test the VC. Cisco provides two different syntaxes for configuring ATM PVCs. Here is an example of the older method:

Router2#configure terminal 
Enter configuration commands, one per line.  End with CNTL/Z.
Router2(config)#interface ATM0/0
Router2(config-if)#no ip address
Router2(config-if)#exit
Router2(config)#interface ATM0/0.1 point-to-point
Router2(config-subif)#description PVC to New York
Router2(config-subif)#ip address 192.168.250.146 255.255.255.252
Router2(config-subif)#atm pvc 1 0 60 aal5snap 10000 5000 3 oam 5
Router2(config-subif)#exit
Router2(config)#end
Router2#

In IOS 11.3, Cisco introduced a new configuration method for ATM PVCs:

Router2#configure terminal 
Enter configuration commands, one per line.  End with CNTL/Z.
Router2(config)#interface ATM0/0
Router2(config-if)#no ip address
Router2(config-if)#exit
Router2(config)#interface ATM0/0.1 point-to-point
Router2(config-subif)#description PVC to New York
Router2(config-subif)#ip address 192.168.250.146 255.255.255.252
Router2(config-subif)#pvc 0/60 
Router2(config-if-atm-vc)#vbr-nrt 10000 5000 30
Router2(config-if-atm-vc)#oam-pvc manage 5
Router2(config-if-atm-vc)#exit
Router2(config)#end
Router2#

Discussion

These two configuration examples do exactly ...