I've read quite a few threads on this already, but unfortunately I still need a little more assistance.

I'm setting up an IPSec tunnel between a main office and a branch office.(I read a post like this already, but it didn't help me too much)

First off, I'm completely new to Linux IPSec, I've been using Linux for awhile now, I'm not a complete beginner, though.

At our main office we have our Linux firewall running shorewall which will I hope can also double as our IPSec gateway.

At our remote office we have a Linksys VPN router. We need to have the linksys router and the linux firewall be able to communicate through IPSec for one of our workers that moved. I have been reading the Shorewall documentation, but it really hasn't helped me too much.

I'm using Debian Etch on the Linux Firewall, I can't remember the kernel version though.

Where would anyone suggest I start reading to get this figured out?

Thanks in advance.

First I don't think that the VPN router can connect to the IPSec tunnel at the main office, as I believe that the router acts as a VPN server. This is the setup I am familiar with in terms of most commercial routers. I might recommend you actually use a Linux server to connect or use a client on the one person who needs it computer.

Okay if we go with the VPN route do I need to do anything to our linux firewall/gateway to allow the VPN router to connect?