I have just installed a Cisco 5505 between our Internet modem and SBS2K3 with ISA 2004.  Everything works fine except for VPN.  After talking with Cisco I have been told that the 5505 will not forward gre because we are using PAT without obtaining another static IP address.  The Cisco tech suggested using Cisco VPN and creating L2TP VPN.  This has been configured but all connections coming from outside the office terminate at the Cisco 5505 and I have not been able to figure out a way to allow access to the internal network.  Can this be done in ISA or will I need to come up with a completely different VPN solution.  I am getting ready to hire an outside consultant but thought I would take one last stab at this.  Also, I am not completely sold on the L2TP VPN because I have remote Mac users and PPTP worked so well with them.  I think my Macs will have to start using Cisco client if we can even get access to the internal network.

 

Anyone have any thoughts or suggestions on this.  I am working with a Cisco tech but he has no ISA/SBS background which is what I really need.

 

Thank you.