AIS AI2524 Configure XOT Remote X.25 Route, X25 route #position x121-address cud, Number

Chapter 12: AI2524 X.25 Configuration Steps

dress. As a result, all outgoing calls from the VAX are sent to cisco on-tymnet for further processing.

On the router named cisco-on-tymnet, you enter these commands:

x25 route vax-x121-address ip cisco-on-vax x25 route .* interface serial 0

These commands force all calls with the VAX X.121 address to be sent to the router with the VAX connected to it. All other calls with X.121 addresses are forwarded out to Tymnet. If Tymnet can route them, a Call Accepted packet is returned, and everything proceeds normally. If Tymnet cannot handle the calls, it clears each call and the Clear Re- quest packet is forwarded back toward the VAX.

Configure XOT (Remote) X.25 Route

A remote X.25 route is one that crosses a TCP connection. Such routes are called X.25-over-TCP, or XOT, routes. (XOT was previously called remote routes or tunneled routes.

When an incoming call needs to be forwarded, two fields in the X.25 routing table are consulted to determine a remote X.25 route:

zDestination X.121 address

zX.25 packet's Call User Data (CUD) field (optional)

When the destination address and the CUD of the incoming packet fit the X.121 and CUD patterns in the routing table, the call is forwarded.

You can also specify an XOT source that causes the XOT TCP con nection to use the IP address of a specified interface as the source ad- dress of the TCP connection. If, for instance, a loopback interface is specified for the XOT connection's source address, TCP can use a pri- mary interface or any backup interface to reach the other end of th connection. However, if a physical interface address is specified as the source address, the XOT connection is terminated if that interface goes down.

In global configuration mode, configure an XOT route (thus adding it to the X.25 routing table):

x25 route [#position] x121-address [cud

pattern] ip ip-address[xot-source type

number]

August 1997	Page 12-33
2524UM