02-11-2010 08:16 AM
I am having an issue where a PPTP client can successfully connect to an external VPN out of our coporate network.
Using the same, laptop, profile, I cannot connect to the external VPN.
Laptop OS: XP Pro SP3
Can anyone shed some light or point me in the right dircetion on where to look for this?
02-12-2010 04:17 PM
Make sure the PPTP Application Layer Gateway (ALG) is turned on for the firewall.
I'm assuming this function is on the Netscreen 25 in a similar way to the SSG series that I am used to. In the SSG this is found under the security tab.
Basically PPTP and other applications like this use random ports that get negociated during the connection. The firewall has to be aware of the application to allow the traffic. When you enable the PPTP ALG this is done and the connections can proceed.