Well if it's the same VPN server you could just block all traffic to the
specific IP.  

-----Original Message-----
From: Jim Naslund [mailto:jnaslund at gmail dot com] 
Sent: Tuesday, October 11, 2005 9:16 AM
To: m0n0wall at lists dot m0n0 dot ch
Subject: [m0n0wall] Blocking Outgoing VPN Access

Hi,

I'm trying to block VPN access from my network because people are
connecting to a nearby campus with VPN and downloading
through direct connect that way. I made a firewall rule that rejected
UDP
packets destined for port 500 but this did not prevent access.
The VPN connection I'm trying to block uses IPSec. Any suggestions?

Jim