User manual

Appendix D – Recovering From a Failed Upgrade
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Appendix D – Recovering From a
Failed Upgrade
If the Heart beat (or H/B) LED is not flashing 20 – 30 seconds after power is supplied, the
SG unit is unable to boot correctly. This is usually because the firmware inside the SG
unit has been written incorrectly or incompletely, or in rare cases it may have become
corrupted.
In this situation, a recovery boot reprograms the SG to bring it back to a usable state.
This can be done using the Netflash executable if you are running Windows, otherwise
you have to set up a BOOTP (DHCP) server.
Both procedures are outlined below.
Note
A Netflash that contains the firmware that shipped with your unit is located in the
\firmware directory on the SG CD. A Netflash containing the latest firmware for your SG
unit can be obtained from SG customer support.
Always attempt a recovery boot before requesting an RMA from customer support.
Recovery using Netflash
The following details the steps required to perform a recovery boot using the Netflash
program on a Windows PC.
Attach the SG unit's LAN port or switch directly to your PC using a crossover cable.