1) Communicate through the VPN
2) Look at the IPSec-counters under "shw crypto ipsec sa"
Don't stop after you've improved your network! Improve the world by lending money to the working poor:
Also if you are using an ASA a packet tracer will do it
You will need to run it twice as the first time the encryption will drop it! The second time if properly setup the VPN will go up
After the packet-tracer do a
-show crypto isakmp sa
-Show crypto ipsec sa