Cisco IOS Wide-Area Networking Configuration Guide - Free Books

Configuring X.25 and LAPBX.25 and LAPB Configuration ExamplesObserve the weighting of 100 on subinterface 1.1 over 200 on subinterface 1.2 in the ip route command,because subinterface 1.1 is the primary route and 1.2 is the secondary route. The latter becomes activatedonly when subinterface 1.1 is unable to function. Weights make for predictable routing events andtherefore promote the concept of primary and secondary routes.Router(config)# interface serial1Router(config-if)# encapsulation x25Router(config-if)# x25 address 11111Router(config-if)# exitRouter(config)# interface serial1.1 point-to-pointRouter(config-subif)# ip address 172.30.22.1 255.255.255.0Router(config-subif)# x25 map ip 172.30.22.2 22222Router(config-subif)# x25 retry interval 60 attempts 10Router(config-subif)# exitRouter(config)# interface serial1.2 point-to-pointRouter(config-subif)# ip address 172.30.22.1 255.255.255.0Router(config-subif)# x25 map ip 172.30.22.4 44444Router(config-subif)# exitRouter(config)# ip route 172.30.11.1 255.255.255.0 serial1.1 100Router(config)# ip route 172.30.11.1 255.255.255.0 serial1.2 200X.25 Remote Failure Detection and the Backup Interface ExampleThe following configuration example is an alternative to the method previously described. X.25 remotefailure detection is configured on subinterface 1.1, and interface 2 is made the backup interface. The x25retry command has been set with an interval of 50 seconds up to a maximum of 20 attempts. In thisexample, there is no need to configure any IP static routes (as is done with the above configuration)because the backup interface is functioning as the secondary route. In other situations, there may be aneed for static IP routes, depending on how the backup interface is configured.For more details about backup, see the backup interface command in the chapter in the Cisco IOS DialTechnologies Command Reference.Router(config)# interface serial1Router(config-if)# encapsulation x25Router(config-if)# x25 address 11111Router(config-if)# exitRouter(config)# interface serial1.1 point-to-pointRouter(config-subif)# ip address 172.30.22.1 255.255.255.0Router(config-subif)# x25 map ip 172.30.22.2 22222Router(config-subif)# x25 retry interval 50 attempts 20Router(config-subif)# backup interface serial2Router(config-subif)# exitRouter(config)# interface serial2Router(config-if)# encapsulation x25Router(config-if)# x25 address 11111Router(config-if)# ip address 172.30.22.1 255.255.255.0Router(config-if)# x25 map ip 172.30.22.3 33333Router(config-if)# exitX.29 Access List ExampleThe following example illustrates an X.29 access list. Incoming permit conditions are set for all IP hostsand LAT nodes that have specific characters in their names. All X.25 connections to a printer are denied.Outgoing connections are list restricted.!Permit all IP hosts and LAT nodes beginning with “VMS”.!Deny X.25 connections to the printer on line 5.!83