User`s guide

Chapter 5: Diagnostics and Troubleshooting
FDDI Dual-Attached Intelligent Module User’s Guide Page 5-3
5.2 OPERATIONAL DIAGNOSTICS
Operational diagnostics for the 3F00-01/3F55-01 consist of built-in local
and remote loopback tests. These tests can be initialized by your network
management system, and the test results are reported back to the NMS.
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 into 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 (after looping) without errors. For remote
loopback tests, the ATX creates LLC Type 1 test packets.
5.2.1 Troubleshooting
Refer to your ATX User Guide for additional guidelines on
troubleshooting if the problem is outside the scope of this manual. Some
common things to check are provided in the sections that follow.
Status LED Not Lit
If the STATUS LED is off on your 3F00-01 or 3F55-01:
1. Check the module status using the LCM
status command.
2. Restart the module using the LCM
offline and online commands.