Enterasys Networks Fast Network 10 - Manual (Page 107)

Responses to Failures at Power-up
Fast Network 10 User Guide Page 6-3
6.1.3 Software Checksum Comparison
When the FN10 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 FN10 will automatically use its backup version of software. A backup
version of software is always stored in non-volatile memory.
The operational parameters of the FN10 software are also protected by a
checksum comparison. When the FN10 reboots, if the operational
parameters of the FN10 fail a checksum test due to a power failure in the
midst of a previous update, the FN10 automatically uses its backup
version of the parameters.
6.1.4 Power-up Diagnostics Results
After completion of the power-up diagnostic sequence, both the Power
(Pwr) and Ready LEDs located on the front panel of the FN10 should be
on.
6.2 RESPONSES TO FAILURES AT POWER-UP
How the FN10 responds to failures detected during power-up depends on
the seriousness of the failure. For example, the FN10 will operate if a
non-critical component, such as the out-of-band management port, fails
diagnostics. However, in the event of a critical failure, such as a failure of
the main element processor, the FN10 will halt execution and will not
boot to operational mode.
6.3 DIAGNOSTIC LOOPBACK TESTS
You can perform local and remote loopback tests on any Ethernet port
while the FN10 is operational.
NOTE
A backup version of the operational parameters is always
stored in non-volatile memory before any update is attempted.