I am trying to create a front end back end firewall solution using Pix Version 6.3(5) as my front end and Microsoft ISA server 2004 as my backend. I am trying to pass Microsoft client VPN connections thru the Pix firewall and terminate them on the ISA server. I have added these commands to the Pix.
access-list outside_acl permit tcp any host 64.206.48.XX (external address of Pix)
static (inside, outside) 64.206.48.xx 22.218.0.xx netmask 255.255.255.255 0 0
22.218.0.xx is the "external interface" of the ISA server. With this configuration, inside users can access the internet, but any attempts to create and terminate a external VPN connection receives the error "remote computer did not respond." What do I need to do to pass pptp and l2tp traffic to the ISA server?