cisco vpn client access behind the (Firewall) Proxy Server

[maha]

I've installed cisco vpn client. It's perfectely working when you are having direct internet connection in your vpn client machine. If your client machine is behind the firewall(or proxy) its not suppoting(not working). Is there any better solution for this problem.

vkarthik@india.com

[turnbull]

The firewall must allow protocol 50 and udp port 500 through.

The VPN client cannot have a PAT device in front of it. This will break the ipsec header.

PAT will only work to a concentrator as the endpoint.

[mmedwid]

What are you VPNing to? A CVPN 30XX? You should just have to click the radio button in the client setup which allow operation through NAT. In fact the latest 3.5 client allows operation through a couple of different NAT scenarios (btw - does anyone out there have an idea what the difference between these two new options and the single option that was offered pre-3.5?) Anyhow - even with earlier versions of the client I've had no problem getting out through firewalls using NAT or firewall using PAT when the far end of the termination was a CVPN 30XX. (PPTP is a different story - that will work with most 1:1 NAT setups but fail with PAT.)