Windows 2003 IPSec through ASA/FWSM

Unanswered Question
Oct 2nd, 2008

Does anyone have any experience setting up a ASA/FWSM to permit an IPSec tunnel b/w Windows 2003 server to pass through? The Microsoft team doing the implementation claims the server behind the FW cannot be NAT'd since their solution has issues with NAT-T. I've configured an identity static and tried NAT 0. It looks like the tunnels establish but data is not passing through.

I have this problem too.
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Matthew Warrick Thu, 10/02/2008 - 11:00

From Microsoft's website, "PPTP traffic uses TCP port 1723 to create and maintain the connection and IP protocol 47 to send data. L2TP/IPSec traffic uses UDP ports 500 and 4500 to create and maintain the connection and IP protocol 50 to send data. Configure your firewall to allow these types of traffic to and from your VPN server."

Your firewall is probably not passing either the GRE or the ESP protocol depending on whether they are running PPTP or L2TP.

dkraut Thu, 10/02/2008 - 11:34

what version of pix os?

6.3 or higher, this should fix it >

fixup protocol pptp 1723


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