Using the Traceroute command

Traceroute displays the route that a packet takes to reach the requested target. Traceroute starts at the first router and uses a series of UDP probe packets with increasing IP time-to-live (TTL) or hop count values to determine the sequence of routers that must be traversed to reach the target host. The Traceroute function can be invoked by either the TSO TRACERTE command or the z/OS® UNIX shell traceroute/otracert command.

The packetSize option lets you increase the IP packet size to see how size affects the route that the Traceroute packet takes. It also shows the point of failure if a destination address cannot be reached.

If equal-cost multipath routes exist in the IP routing table for outbound IP traffic to reach a remote host, use the Traceroute SRCIP/-s option or the INTF/-i option to select a home IP address (for example, VIPA) for the source IP address and a routing interface with the attached equal-cost multipath route. Alternatively, for routing interfaces associated with an IPv6 link-local address, you can append the name of the routing interface as scope information to the IPv6 link-local address of the remote host. When running multiple TCP/IP stacks on the same MVS™ image, specify the TCP/-a parameter, with the scope, to indicate the stack to which the routing interface is configured. Whenever applicable, use one of these options to test connectivity. For more information about using scope, see the information about support for scope in z/OS Communications Server: IPv6 Network and Application Design Guide.

For the complete syntax of the TSO TRACERTE and z/OS UNIX traceroute/otracert command and examples of command output, see the z/OS Communications Server: IP System Administrator's Commands.