6.5 Configuring EIGRP
6.5.5 Controlling SAP updates
If an IPX EIGRP router has another IPX EIGRP router as its link partner, you can configure either the router to send SAP updates periodically or when a change occurs in the SAP table. When no IPX EIGRP peer is present on the interface, periodic SAPs are always sent.

On serial lines, by default, if an EIGRP neighbor is present, the router sends SAP updates only when the SAP table changes. Overhead is greatly reduced if a router updates other routers only when a change occurs.

On Ethernet, Token Ring, and FDDI interfaces, by default, the router sends SAP updates periodically. To reduce the amount of bandwidth required to send SAP updates, you might want to disable the periodic sending of SAP updates on LAN interfaces. Do this only when all nodes out this interface are EIGRP peers; otherwise, loss of SAP information on the other nodes will result. If a router's LAN interface connects to a NetWare server, as shown in the figure, do not disable periodic updates. However, Figure shows that incremental SAP updates on RTC's E0 can safely be configured.

To configure incremental SAP updates using EIGRP, issue the ipx sap-incremental eigrp command, which has the following syntax:

router(config-if)#ipx sap-incremental eigrp autonomous-system-number [rsup-only]

The rsup-only keyword is used to indicate that on this interface the system uses EIGRP to carry reliable SAP update information only. RIP routing updates are used, and EIGRP routing updates are ignored.

Configure incremental SAP for RTC as shown in Figure .

Note that in Figure , RTC does not need to run IPX RIP. Thus, it is explicitly disabled by using the command no ipx router rip in the configuration Figure .