IPv4 considerations for Routing Information Protocol

If using Routing Information Protocol (RIP) services and Host Route advertising is not supported by adjacent routers (that is, inability to learn host routes), the following restrictions for VIPA addresses must be applied to benefit from fault tolerance support:

• If you use subnetting and VIPA addresses are in the same network as the physical IP addresses, the subnetwork portion of any VIPA addresses must not be the subnetwork portion of any physical IP addresses in the network. In this case, assign a new subnetwork for the VIPA address.
• If subnetting is not used on any physical interface, the network portion of any VIPA addresses must not be the network portion of any physical IP addresses in the network. In this case, assign a new network for the VIPA address, preferably a class C network address.

If using RIP services and Host Route advertising is supported by adjacent routers, the network or subnetwork portions of VIPA addresses can be the same across multiple z/OS® TCP/IP stacks in the network. To enable Host Route advertising in OMPROUTE, configure RIP_Interface Send_Host_Routes=YES.