Cisco 800 Series to ISA 2004 site to site VPN

[glen.bingham]

Hi,

I have been trying to get a site to site IPSec tunnel up and running from our branch office running a Cisco 857 Router to our Main office running ISA 2004.

I can create a Site to Site VPN connection using SDM and can get the tunnel established. But when I try and ping an IP address at the Main Office from my Branch Office I get "Destination net unreachable".

I have found several documents on setting up site to site connections between ISA and PIX but there is no real example I can find for the router I am using.

I presume that it is possible but as I am new to Cisco VPN tunnels I need some help in getting this working.

[thomas.chen]

This could be due to many things, primarily looks like a routing issue. Make sure you have the necessary routing working. Also, if you are using NAT, make sure the routing for the NATed addresses are working fine too.

[richardwhit]

Maybe this article will help http://www.microsoft.com/technet/prodtechnol/isa/2004/plan/ipsecvpn.mspx

Have you monitored the ISA Server to see if its dropping the traffic, remember it will drop everything by default.