Cisco Device Troubleshooting Commands

 

sh crypto session : shows active VPN sessions
sh crypto session detail : shows details of VPN sessions

sh crypto ipsec sa : show ipsec saís between peers
sh crypto isakmp sa : show internet security association management protocol security associations between peers.
sh crypto engine connection active : show traffic sent. Encryptions outbound decryptions inbound.

debug crypto isakmp errors : will give you breif info when isakmp throws an error
debug crytpo isakmp : it is a detailed output of the entire phase 1 negotiation processes - on a rolling basis - so if your VPN is broken, it's almost a non-stop output.

clear crypto isa sa : reset VPN tunnel (this brings tunnel offline breifly)

 

Sh log : shows the log (if availiable) of logging messages
Sh int gix/x : shows the interface counters of a device

 

monitor session | source int xxxx
monitor session | dest int xxxx
sh monitor

 

 

sh proc cpu history : show processor history in graphic format
sh proc memory sorted : show memory usage history
sh int gi x/x : shows interface counters
sh log : shows the log (if availiable) of logging messages