Odds are some router ahead of you will rewrite that port anyhow. Even if windows kept it the same, any router in front of that doing NAT would likely randomize the source port when doing translation.

What do your config files look like?

Okay so the fix was pretty simple.  For anyone with a similar setup, you need to put local 1.2.3.4 (your WAN IP address) into the "Custom Options" field in the OpenVPN configuration page to bind the service to the specific interface.

Ah ok, i was under the impression that the server is running on a pfSense. Do you control the server? Because if it reply has a different source IP than what you connect to, there is not much you can do to get it working.

Downloaded RC1 that fixed all of bugs and looked like that fixed all of my problems with OpenVpn

This was fixed a couple weeks ago, it should be fine in current snapshots.

I have a rough draft of the OSPF method that I've sent to some of our commercial support subscribers before, but it's still a little rough around the edges. The other method hasn't had any documentation at all yet, I'm not sure anyone has ever done that exactly as I described. You could put up a bounty for the documentation if you want to speed it up. It will happen eventually, whether it ends up on the Doc Wiki, in our 2.0 book (when that gets going), but funding always speeds up the process.

Could you let me know what exactly you did to get vyprvpn working? maybe a screenshot of the entire openvpn client settings page or something like that?

thanks for your help, my pfsense is right working since my last post  ;D Now I'm able to use my windows 2008R2 server as authentications server for pfsense, openVPN and squid using a LDAP connection.

Fixed it by enabling arp proxing for the the /24 vpn subnet.

Solved using viscosity. Nice piece of software.

Here is the update, I switched from shared key to SSL and TCP to UDP, now it seems to be working. Will monitor this line for couple of days to see if I've further problems.

I think that you should see only the VPN call in WAN interface, once created the tunnel all comunications are between LAN and VPN interface.

yes, routes are ok, but you may need to configure also a firewall rule in pfsense or in local firewall in your server.

I'm in the same boat as you. I haven't been able to set this up in pfSense 2.0. Hopefully someone will have an answer at some point.

So, I tried replacing the Linux+shorewall router with pfSense, to see if it was something strange with how I was configuring the Linux client.  Still no joy.  Then I tried using IPsec instead of OpenVPN, and it worked!  This may be the first time in history IPsec has actually made something easier. ;)