Correcting timeout problems

A Ping timeout message can occur for many reasons, and various techniques can be used to identify whether the problem is the local z/OS® server or a remote host or router.

Base your actions on the possible reasons for a timeout, as shown in Table 1.
Table 1. Diagnosis of a timeout
If the problem is... Then use these diagnostic techniques
The device is not transmitting packets to the local network. Use Netstat DEVLINKS/-d to collect information to help you diagnose the problem. (See DEVLINKS/-d report option in z/OS Communications Server: IP System Administrator's Commands.)
The remote host is not receiving or transmitting packets on the network. Use Netstat ARP/-R to display the IPv4 entry for the remote host. (See the ARP/-R report option in z/OS Communications Server: IP System Administrator's Commands.)

Use Netstat ND/-n to display the IPv6 entry for the remote host. (See the ND/-n report option in z/OS Communications Server: IP System Administrator's Commands.)

The remote host does not have a route back to the local z/OS server. Use Netstat ROUTE/-r on the remote host to make sure that it has a route back. (See ROUTE/-r report option in z/OS Communications Server: IP System Administrator's Commands.)
An intermediate router or gateway is not correctly forwarding IP packets. Use a packet trace. (See TCP/IP services traces and IPCS support.)
The IP reassembly timeout value might be set too low. See the TCP/IP Profile statements, IPCONFIG and IPCONFIG6, in z/OS Communications Server: IP Configuration Reference.