Correct approach to testing VPNs
Posted on 2013-01-14
I'm in the process of upgrading some old firewalls to some new ones. There are some VPNs setup already. The config from the old fw's has been copied to the new ones. I'm going to swap the cables from the relevant interfaces. I'm looking for a way to verify that the VPNs are up and are passing traffic on the new firewalls after I swap the cables. I'm used to having an object-group of hosts. I wanted to develop a list of tests for example ping some host (on the other side of the VPN) or telnet to it on port 22 or 3389. However the VPNs configured on these firewalls match traffic from network to network. I'm not sure what is used across the VPNs as they are customer systems.
What I've come up with so far:
Use "sh crypto isakmp sa" before and after (but that counts on something generating VPN traffic to bring the tunnel up)
Use the ping command to source the ping from the correct network
Use "sh crypto map"
I'm not sure what the correct approach is here.