I have another work around my coworkers and I used to get back in our 3750 we were testing this upgrade on using SNMP. If it's configured it's possible to do the following:
Prepare a file on a tftp server, call it what you want. Inside we used something like:
aaa authentication login default local
aaa authorization exec default local
username recover password this
end
Push the above configuration to the device by setting the necessary values and then activating. This command should do all that in one, just edit the IP address and th line below it to match the filename we created above on the tftp server.
snmpset -v 2c -c private Device .1.3.6.1.4.1.9.9.96.1.1.1.1.2.50 i 1 \
.1.3.6.1.4.1.9.9.96.1.1.1.1.3.50 i 4 \
.1.3.6.1.4.1.9.9.96.1.1.1.1.4.50 i 1 \
.1.3.6.1.4.1.9.9.96.1.1.1.1.5.50 a "10.0.0.2" \
.1.3.6.1.4.1.9.9.96.1.1.1.1.6.50 s "Router.cfg" \
.1.3.6.1.4.1.9.9.96.1.1.1.1.14.50 i 4 \
Check on the status using the following command, just make sure to change the host and community string:
snmpwalk -v 2c -c private 10.0.0.1 .1.3.6.1.4.1.9.9.96.1.1.1.1.10.50
Possible integer responses to this above command are waiting(1), running(2), successful(3), failed(4). If it returns 1 or 2, just keep trying until it reaches 3 or 4. If it times out, keep trying.
When done, destroy the row:
snmpset -v 2c -c private 10.0.0.1 .1.3.6.1.4.1.9.9.96.1.1.1.1.14.50 i 6
At this point we were able to log in and downgrade without leaving our seats. Of course, this does require SNMP with RW to be configured and it may time out occasionally due to the CPU utilization being high. Hope this helps some others.
