User guide

Chapter 5: FN100 Diagnostics and Troubleshooting
Page 5-2 Fast Network 100 User Guide
5. After several more seconds, the Ready LED will stay on, indicating
that the power-up diagnostics sequence is complete.
In addition, the Port Link LEDs will turn on for those ports with good
links and the Segment Status LEDs will turn on (or flash) when the
selected status condition is present.
5.1.2 Specific Power-Up Tests
The power-up diagnostic tests performed on the FN100 include:
• ROM checksum test
• Instruction/Data memory test
• Address database memory test
• Ethernet controller test
• Packet memory test
• Shared RAM test
• Ethernet data loopback test
5.1.3 Software Checksum Comparison
When the FN100 reboots, its operational software is verified by a
checksum comparison before it is loaded. If the software fails the
checksum test due to an interrupted new software distribution procedure,
the FN100 automatically uses its backup version of software. A backup
version of software is always stored in non-volatile memory.
The operational parameters of the FN100 software are also protected by a
checksum comparison. When the FN100 reboots, if the operational
parameters of the FN100 fail a checksum test due to a power failure in the
midst of a previous update, the FN100 automatically uses its backup
version of the parameters.
NOTE
If the Ready LED does not stay on, contact Cabletron Systems
Technical Support.