OS X: how to figure out what prevents L2TP/IPSec from running correctly

Question

It seems that an old installation of Cisco Anyconnect prevents the OS X built-in L2TP/IPSec client from running (I posted a question here: OS X 10.7, can't log into any L2TP VPN server, but didn't get any results).

What is the best way to figure out if anything is taking over the sockets or ports required for L2TP/Ipsec? I tried some basic netstat and lsof and couldn't see anything relevant.

Answer 1

Ok, I figured it out. It wasn't ports and sockets. Turns out that something (possibly CiscoAnyconnect) has unloaded racoon on startup. To fix (with Anyconnect uninstalled) do the following:

launchctl load -w /System/Library/LaunchDaemons/com.apple.racoon.plist

You may also start racoon manually by:

sudo /usr/sbin/racoon