[expert] broken VPN, set 'skip' protocol 57

[Daniel Woods]

I've recently installed and configured a new linux machine as
a web server and firewall (connected to cable modem).
My VPN access to work (from NT) used to work but now it can't
seem to connect.  My IP Masq is basically DENY everything and
ALLOW forward from local 192.168.*

I was told that I needed to open t up to allow 
"skip protocol 57" ?  Huh!
What is skip protocol, and how do I allow it through the
firewall ?

Thanks... Dan.