[c-nsp] Cisco/HP 3020 refuses telnet

[Phil Mayers]

matthew zeier wrote:
> I have a Cisco/HP 3020 blade chassis switch that all of a sudden stopped 
> accepting telnet (because rancid started to fail config checks).
> 
> Short of rebooting I'm not sure how to fix.  I can login on the console 
> (using tacacs auth of all things, so IP works) and can ping it.  But 
> telnet gives a connection refused.  I've even go so far as changing the 
> IP address on fa0.
> 
> Any clues/ideas?

Something might have eaten all the VTYs.

If that's so, you can actually see who's connected via SNMP (if you've 
got it setup) and even terminate their connection - a colleague of mine 
discovered this:

snmpwalk -c READCOMM -v 2c $SWITCH .1.3.6.1.2.1.6.13.1.1
TCP-MIB::tcpConnState.192.168.1.1.22.192.168.1.41.1022 = established(5)
# lots more

then:

snmpset -c WRITECOMM -v 2c $SWITCH 
TCP-MIB::tcpConnState.$DSTIP.$DPORT.$SRCIP.$SPORT i 12

You'll want to fix this permanently if this is the problem:

line vty 0 15
  session-timeout 1440
  exec-timeout 1440 0