AIS AI2524 user manual Create and Configure X.25 Subinterfaces

Chapter 12: AI2524 X.25 Configuration Steps

tination host defined for the protocol. Because only one destination is defined for the interface, the routing process need not consult the des- tination address in the datagrams.

A multipoint subinterface is used to connect hosts for a given protocol. There is no restriction on the number of encapsulation commands that can be configured on a multipoint subinterface. Because the hosts ap- pear on the same subinterface, they are not relying on the router to dis- tribute routing updates between them. When a routing process forwards a datagram to a multipoint subinterface, the X.25 encapsula- tion process must be able to map the datagram's destination address to a configured encapsulation command. If the routing process cannot find a map for the datagram destination address, the encapsulation will fail.

Note:	Because of the complex operations dependent on a sub-
	interface and its type, the router will not allow a subinter-
	face type to be changed, nor can a subinterface with the
	same number be re-established once it has been deleted.
	After a subinterface has been deleted, you must reload the
	Cisco IOS software (by using the reload command) to
	remove all internal references. However, you can easily
	reconstitute the deleted subinterface by using a different
	subinterface number.

Create and Configure X.25 Subinterfaces

In interface configuration mode, create and configure a subinterface by completing the first task and one or both of the second tasks:

1.Create a point-to-point or multipoint subinterface.

interface serial number.subinterface-number[point-to-point multipoint]

2.Configure an X.25 encapsulation map for the subinterface:

x25 map protocol address [protocol2 address2 [... [protocol9 address9 ]]] x121- address [option]

And/or establish an encapsulation PVC for the subinterface:

x25 pvc circuit protocol address [protocol2 address2 [...[protocol9 address9 ]]] x121- address [option]

August 1997	Page 12-15
2524UM