An image always explain better than words - this is the basic (in this matter) of my network:

http://asgeir.net/Image1.gif

Alright, my ISP have "given" me a /29 subnet of public static IP's. Meaning I have 5 static public IP's for my needs Server 1 is a ClarkConnect installation, configured to share folders with help from Samba. I can successfully access these folders from my Windows PC. Now, I would really like to use Server 2 (Debian Sarge) for shared folders. I plan on replacing ClarkConnect with a Pfsense (OpenBSD), and I guess it will be very difficult to have network shares on that box.

So my question is: How do I set up my Debian Sarge box with network folders that can be accessed from clients under Server 1? I'm not hoping for a full blown guide here, but a hint on what alternatives there are! Pros and cons, and maybe a link to good reading?

One guess (remember - I'm not a linux guru like many of you in here!) would be to use NFS with IPSEC? CIFS with OpenVPN? Do I need tunneling? Encryption? It's all just phrases I have picked up after reading and searching the whole day... It's not easy to figure out where to start...

So - thank you for *any* advices, they could all be valuable

For mounting remote directories between Linux servers I would recommend to use sshfs. It mounts remote directories using an encryption tunnel and even with private keys. You only need to install sshfs on Server1 then mount the remote directory of Server2 on it, like so:

sshfs user1@server2 /var/newdir

If you setup empty keys then you don't have to use a password. However, be sure to limit access using /etc/hosts.allow.

Afterward you can make /var/newdir a share in Samba.

sshfs - I will read up un that, thanks for suggestion. Though, I find it hard to believe that no other modifications needs to be done except for editing hosts.allow on my Debian Sarge server? And also, if I plan on replacing ClarkConnect with pfsense (OpenBSD), this could be hard to do. It only have options for OpenVPN and IPSEC...

With hosts.allow you can limit which workstations are allowed to connect to server2; that way you can tighten security even further for ssh. You may want to include the mount in /etc/fstab if you want it to mount autmatically upon startup. As far as the other Unix brands, it doesn't matter, as long as they have ssh-server running. You only need to setup sshfs on the system that will contain the mounted directory and not on the server that contains the shared directory.