System information

Troubleshooting IBM

Book Title

10-246

CIP: Host Cannot Reach Remote Networks

Symptom: Mainframe host cannot access networks across a router.

Table 10-17 outlines the problem that might cause this symptom and describes solutions to that

problem.

Table 10-17 CIP: Host Cannot Reach Remote Networks

CIP: Host Running Routed Has No Routes

Symptom: A host running routed has no routes to remote networks.

Table 10-18 outlines the problems that might cause this symptom and describes solutions to those

problems.

Table 10-18 CIP: Host Running Routed Has No Routes

Possible Problem Solution

Missing or misconﬁgured

IP routes

Step 1 If the mainframe host is unable to communicate with networks on the

other side of the router, try to ping the remote network from the router.

If the ping succeeds, proceed to Step 4.

Step 2 If the ping fails, use the show ip route privileged exec command to verify

that the network is accessible by the router.

Step 3 If there is no route to the network, check the network and router

conﬁguration for problems.

Step 4 Verify that the host connection is active by pinging the host IP address

from the router. If the ping is unsuccessful, see the section “CIP: Router

Cannot ping Host or Host Cannot ping Router” earlier in this chapter.

Step 5 Issue the netstat gate command on the host and check for a route to the

network.

Step 6 If a route does not exist, make sure the host is using the address of the CIP

in the router as the default route. If it is not, add a GATEWAY statement in

the TCP/IP proﬁle that points to the network, or set the CIP in the router as

the default route using a DEFAULTNET statement in the TCP/IP proﬁle.