We are a user of pfSense Firewall / Router and we were having some
problems using MacOS X Mountain Lion builtin VPN client with the pfSense
VPN server. On session rekey, ~45 minutes, it would prompt for username
and password. On our main VPN system at work, VPN worked fine and I
noticed the Cisco system did not do XAuth during rekey. I googled to see
if anybody else had this issue on pfSense, found many posts on the issue
but no fixes. I figured I would see could find a solution and I came up
with the following patch witch I submitted to pfSense project.

One of the responses wondered if I had considered submitting this
upstream and so here I am. Hopefully my implementation has enough merit
for consideration.

Thanks for you time,