User guide

Chapter 6. Managing the Router 273
Identifying Fatal Boot Failures
Fatal boot failures can be identified by the LEDs light patterns displayed on the front panel of the router.
Note: Normal LED states are described in the Hardware Reference section of the Quick Start Guide.
TEST, LNK, WAN, and LANT display these fatal errors according to the following LED patterns:
0-0-0-G CPM fail
0-0-G-0 Timer fail
0-0-G-G Bad FCS
0-G-0-0 DRAM fail
0-G-0-G Interrupt fail
0-G-G-0 SCC fail
Y-0-0-0 CPU step fail
Y-0-0-G Ethernet loop fail
FG-0-0-* Wait stuck in the boot menu; kernel file could be missing (green LED blinking very rapidly)
G-0-0-* Green occasionally blinks off (at 10-second intervals). The router is issuing BootP requests.
where
0 = the LED light is off
G = the LED light is on, blinking green
FG = the LED blinking fast
Y = the LED blinking yellow
* = the LED could be on, off, or blinking
Any other combinations of the four LEDs flashing in a regular pattern will indicate an internal error. Should this
occur, return the router to the factory for repair or replacement.
Note: Non-fatal errors are not displayed by the LEDs, but they do prompt the system to print explanatory
messages on the console.
Software Kernel Upgrades
Booting and Upgrading from the LAN
You can download a new version of the router software kernel using a TFTP server that already exists on the
LAN. The following steps demonstrate how to boot the router software from the network and copy the image from