Hey all, I know that it's possible to run GRE over and IPsec tunnel but I am wondering if anyone here has seen some good documentation (besides the man pages) or a howto on setting this up. I'm trying to config my OpenBSD 4.0firewall to interop with a route-based VPN network with a mix of Fortigate and Netscreen firewalls. Fortigates and Netscreens both use GRE interaces as "tunnel interfaces" when creating route-based VPN tunnels. Right now all endpoints are using un-numbered (0.0.0.0/0) GRE interfaces and so I would like to use a similar configuration on the OpenBSD side but I am just wondering how to accomplish this as I am uncertain how to bind the GRE interface to a tunnel.
Right now I have a hub-and-spoke VPN network using static routes to route traffic across the VPN. Each spoke endpoint has a static destination route of 10.1.0.0/16 which is sent over GRE interface. The only exception to the hub-and-spoke VPN is my OpenBSD firewall which I have to create VPN tunnels to every spoke network I need access to (quite painfull). On my OpenBSD box I would like to be able to use a single static destination route of 10.1.0.0/16 to send this traffic over a GRE interface to get to the rest of the VPN network. Here's a snippet of the hub-and-spoke VPN network: 1.1.1.1 ---------------- OpenBSD 10.1.1.0/24 ---------------- | | | | 2.2.2.2 ---------------- Fortigate (Hub) 10.1.2.0/24 ---------------- | | | | 3.3.3.3 ---------------- Juniper 10.1.3.0/24 ---------------- Thanks in advance for your help. Cheers, -Chris