Cisco IOS Wide-Area Networking Configuration Guide - Free Books

Configuring X.25 and LAPBConfiguring X.25 RoutingNoteYou must include a selection option or a modification option in an x25 route command.• disposition-options—Where the VC will be forwarded or whether it will be cleared. You arerequired to use one of the following disposition elements:– interface serial-interfaceA route to a specific serial-interface will send the VC to an X.25 service on a synchronous serialinterface.– interface cmns-interface mac mac-addressA route to a broadcast interface will send the VC to a CMNS partner reachable on a broadcastmedium at a specified MAC address. The CMNS interface can be an Ethernet, Token Ring, orFDDI interface.– xot ip-address [ip2-address [...[ip6-address]]] [xot-source interface]A route to an xot destination (formerly called a remote or tunneled configuration) will send theVC to the XOT service for establishment of a TCP connection across which the XOT VCpackets will travel. An xot disposition may specify alternate destinations to try if a TCPconnection cannot be established for all preceding destinations.– clearA route to a clear destination will deny further service to the VC by shutting down theconnection.• xot-keepalive-options—You can use neither, one, or both of the following optional xot-keepaliveelements:– xot-keepalive-period seconds– xot-keepalive-tries countConfiguring a PVC Switched Between X.25 InterfacesYou can configure an X.25 PVC in the X.25 switching software. As a result, DTE devices that requirepermanent circuits can be connected to a router acting as an X.25 switch and have a properly functioningconnection. X.25 resets will be sent to indicate when the circuit comes up or goes down. Both interfacesmust define complementary locally switched PVCs.To configure a locally switched PVC, use the following command in interface configuration mod:CommandRouter(config-if)# x25 pvc number1 interface type number pvcnumber2 [option]PurposeConfigures a locally switched PVC.The command options are packetsize in out and windowsize in out; they allow the flow control valuesof a PVC to be defined if they differ from the interface defaults.For an example of configuring a locally switched PVC, see the section “PVC Switching on the SameRouter Example” later in this chapter.To ensure that TCP sessions remain connected in the absence of XOT traffic, use the following commandin global configuration mode :33