[Openswan Users] Examples for config in Windows Roadwarrier setup

[Eric Anderson]

Hi, I'm trying to setup a VPN so that a internal network is available to 
  remote users via IPSec/L2TP since the remote users will be using 
Microsofts client that comes installed on their machine.

I seem to be having problems understanding what values are supposed to 
go in the various left, right, leftnexthop, rightsubnet, etc fields in 
/etc/ipsec.conf.

I was wondering if anyone knows of any HOWTO docs that just gives a 
example that is similar to my situation so I can basically just 
substitute the values for what matches on my network. My basic 
configuration is:

------------    ----------    ------------
| Internal |    | VPN    |    | Business |
| Network  |----| Server |----| DSL      |
------------    ----------    ------------
                                     ||
                                     ||
                                  Internet
                                     ||
                                     ||
-----------    ------------    -----------------
|Remote   |----| Optional |----| Remote Client |
|Client   |    | NAT Box  |    | ISP           |
|(Windows)|    ------------    -----------------
-----------

In this example say we would have the following IP addresses:

VPN Server
----------
Internal Network IP: A.B.C.D
Internal Network Gateway: A.B.C.E
Internet (External) IP: M.N.O.P
Internet Gateway IP: M.N.O.Q


Remote Client
-------------
Internal IP: R.S.T.U
Internal Network Gateway: R.S.T.V
Internet (External) IP: X.Y.Z.W
Internet Gateway IP: X.Y.Z.Q

Given the above info what would I need to put into /etc/ipsec.conf to 
get Openswan to handle the IPSec part (obviously I would need to get 
l2tpd and ppp working still)?

I have been mostly following the instructions at 
http://www.jacco2.dds.nl/networking/freeswan-l2tp.html so far but I 
cannot seem to be able to get ipsec setup properly. Also what holes do I 
need to put in iptables to make sure that none of the IPSec stuff is 
getting dropped? I can't seem to find a definitive source for what 
ports/protocols IPSec uses so I can open those up.

Any help is greatly appreciated.

Thanks,

Eric