SOLVED - failed to begin ipsec sa negotication
As we were having trouble getting the IPsec clients stable after upgrading from 1.2.3 to 2.0.1-RELEASE, I did some research and came up with a solution that seems to work.
The problem was that a connection would be established but no traffic could pass through the tunnel and PfSense would log these lines:
racoon: ERROR: failed to begin ipsec sa negotication.
racoon: ERROR: no configuration found for 188.207.93.***.
Earlier on I wrote a howto on setting up IPsec tunneling for road warriors. I updated it to include my solution for this problem.
Here is the link to the article, I hope it saves some people a couple of hours of troubleshooting.