Cisco 6500 “Environment Checksum in NVRAM Failed”

Had an issue where an older Cisco 6500 switch was rebooted, and the MSFC would not start correctly and gave the following errors: “environment checksum in nvram failed” and “rommon nvram area is corrupted”.

When trying to log into the the module from CatOS (session 15), the console stated that “module 15 is not installed”.  Tried to to manually boot the MSFC from ROMMON, using this helpful guide: but kept receiving the “nvram failed” error.  I was convinced it was potentially a hardware issue, but we physically removed the MSFC card, plugged it back in, and the nvram message disappeared and the MSFC module booted!  Good reminder that sometimes the simplest things can resolve a complex issue.

**Note: If you are running a SUP720, there is a field notice for corrupted NVRAM:


Telnet Commands for ShoreTel Switches – Part 2

I’ve already posted how to enable telnet and get to the shell for ShoreTel (non-V) switches here:

Here are some more advanced commands that I have found useful for troubleshooting:

ifShow – Shows network interface information

lsp_ping “”,100 – Tests LSP UDP connectivity to “”, repeats 100 times

lspConList – Shows connectivity to other switches/servers

lspTelList – Shows all extensions known to switch

lspTelList1 – Shows detailed info for local extensions

lspTelList2 – Shows detailed info for remote extensions

reboot – Restarts the switch

routeShow – Shows the routing table

sip_debug_level=2 – Shows detailed SIP info on the console.  sip_debug_level=0 is the default

**Note** Commands are case sensitive

More commands can be found in the ShoreTel release maintenance guides.