Ethernet Support Guide (for HP-UX 11i v1, 11i v2)

Troubleshooting
Diagnostic Flowcharts
Chapter 4
53
Flowchart 2 Procedures
The procedures in Flowchart 2 are:
• Enter linkloop(1M) to the remote host’s MAC address. If the linkloop result is
successful, continue to the Network Level Tests (Flowchart 3). Otherwise, note which
error was returned.
•Ifloopback failed and the error message returned was “Address has bad format” or
“Not an individual address”, correct the link level address with the proper station
address format and value and repeat the Link Level Test.
• Otherwise, loopback failed because the remote host did not respond. Double-check
the remote host’s MAC address or choose another remote host, and re-enter
linkloop(1M). If linkloop is now successful, continue to Network Level Tests
(Flowchart 3). You may also want to call the node manager of the remote host that
did not respond (if this was the case). If linkloop fails, go to Configuration Tests
(Flowchart 8).
• Note that linkloop cannot be used to test connectivity between end stations if those
stations are separated by a gateway or router. To test connectivity between stations
under these circumstances, run the linkloop test between the router or gateway and
each of the end stations independently, then verify network level connectivity by
using ping between the end stations. If the end stations cannot communicate with
each other, but they can each communicate with the router or gateway, then verify
the routing tables in the router or gateway.
• On HP-UX 11i, linkloop cannot send packets larger than 1500 bytes even if the
MTU size is set greater than 1500. This is a known issue, which is fixed on HP-UX
11i v2 (11.23). On HP-UX 11i, linkloop can however receive packets larger than
1500 bytes if, for example, the packets are sent from an HP-UX 11i v2-based system.