You can use EIGRP as an IPX dynamic routing protocol. As seen in earlier chapters, EIGRP has features found in both distance vector (updates only sent to neighbors) and link state protocols (partial incremental updates and decreased convergence time). To enable EIGRP for IPX, use the major configuration command ipx router eigrp . This command requires an autonomous system number to identify the EIGRP process. Throughout a single IPX administrative domain, the EIGRP autonomous system number must be the same for all routers communicating with IPX EIGRP.
The subcommand network associates an IPX network number with EIGRP, instructing EIGRP to pass routing information about that IPX network number. In the following example, we enable EIGRP for IPX on the Singapore router using autonomous system number 25000. We tell EIGRP to pass routing information about IPX networks 4010 and 2902:
Singapore# configure Configuring from terminal, memory, or network [terminal]? Enter configuration commands, one per line. End with CTRL+Z. Singapore(config)# ipx router eigrp 25000 Singapore(config)# network 4010 Singapore(config-ipx-router)# network 2902 Singapore(config-ipx-router)# ^Z
You can enable EIGRP for all IPX networks on a router using the ipx router eigrp subcommand network all .
When using IPX EIGRP, you can make the IOS send SAP messages periodically or only when a change occurs in the SAP table. EIGRP sends periodic SAP messages by default on LAN interfaces, allowing SAP advertisements to reach IPX servers and clients. Periodic SAP messages are also sent by default on any interface that does not have any EIGRP routers, because the interface can connect to IPX servers and clients .
If an interface has only EIGRP routers, you can configure EIGRP to send SAP messages only when a change occurs in the SAP table. This feature can help reduce the traffic on WAN interfaces that interconnect IOS devices by eliminating periodic SAP messages that consume bandwidth. If an EIGRP router is present on a WAN interface, the default behavior of the IOS is to send SAP updates only when the SAP table changes.
To send SAP messages only when a change occurs in the SAP table, use the IOS interface configuration subcommand ipx sap-incremental-eigrp . This command requires as a parameter the autonomous system number for EIGRP. The output from the IOS EXEC command show ipx servers tells you whether an IPX service was learned from a periodic SAP update or from EIGRP.