User`s guide

Diagnostics and Troubleshooting
7-5
Failure Indicators
If an FDDI or Ethernet module has failed, its front panel STATUS
LED will be off.
NMS Failure Traps
As each module completes its power-up diagnostics, it saves
information on any detected failures. These results are passed to
the NMS when the power-up diagnostics are completed (assuming
the ATX is operational). The results sent to the NMS indicate which
component has failed.
7.3 DIAGNOSTICS WHILE ATX IS OPERATIONAL
The following diagnostics may be performed while the ATX is
operational:
• Local and remote loopback tests on any port.
• Power-up diagnostics on an Ethernet or Token Ring module.
7.3.1 Loopback Tests
Built-in local and remote loopback tests can be used to test
individual ports while the ATX is operational. When in local
loopback, a port is disconnected from its network. The ATX
generates loopback packets for the port, and the port loops the
packets back without sending them onto its network.
During a remote loopback test, the port is in normal operation,
sending, and receiving packets to its network. The ATX generates
loopback packets which are sent out of the port to a particular
destination device on the port's network. The destination device
echoes the packet back onto the network, and the originating port
receives the packet.
For both types of tests, normal operation is indicated when
generated packets are received back without errors. For remote