Host unreachable by way of VIPA address when using SOURCEVIPA

The host could not be reached by way of the VIPA address due to improper coding of SOURCEVIPA and the order of the HOME list , or because routers in the network do not recognize the VIPA address.

When SOURCEVIPA is set, outbound datagrams use the corresponding VIPA address in the HOME list instead of the physical interface IP address. If SOURCEVIPA is set, and a VIPA address precedes any number of physical interfaces in the HOME statement in hlq.PROFILE.TCPIP, then the VIPA address is used on outbound packets in place of the IP address for the physical interface. Use the following steps to ensure that a VIPA is correctly associated with a physical interface:

1. Code SOURCEVIPA on the IPCONFIG or IPCONFIG6 statement.

2. Define your VIPA link.

3. Define your physical links.
   

4. Place the VIPA IP address ahead of the physical interface IP address in your HOME statement within the TCPIP.PROFILE. This will ensure that your VIPA address is associated (reachable) by way of the interfaces listed after it.

You also need to configure IP routers in the network to recognize the VIPA address so that a packet sent to the VIPA address can be properly routed. You can configure OMPROUTE on z/OS to advertise the required routes to the IP routers, or all the IP routers in the network can be statically configured to recognize the VIPA address.