Happy new year to all our ISAserver.org readers and a big "thank you" to all of those who have welcomed me to my new position, taking over the site duties for Tom so he can go to work full-time for Microsoft and help to make the products even better. I'm looking forward to getting to know you better in 2010.
I've seen a number of posts over the last few months on the ISAserver.org message boards about people have problems with PPTP connections when trying to connect to ISA 2006. Some people have mentioned that might be related to SP2, while others apparently don't have a problem.
While the jury is officially still out on what the problem with PPTP might be, one issue might be related to the fact that a Server Publishing Rule was created that grabbed the PPTP ports before RRAS can get them. Actually, PPTP only using a single TCP port, which is TCP port 1723. The other protocol required isn't a port, but a protocol, which is IP protocol number 47 (you don't have to worry about that, the IP protocol number for GRE isn't a problem in the scenarios tha we have seen).
For more information on this problem, check out Saurav Datta's post on the TMG Team Firewall blog over at: https://blogs.technet.com/isablog/