vpn questions

["Rommel, Florian" <Florian.Rommel@quartal.com>]

I asked a while back about ipsec and got a general answer that urged me to read on, which i did and i got a nice vpn connection going between a windows box and a openbsd box. All well BUT!! (there's always a but(t)), currently at my office we have vpn connections to severall clients, yet they all dont have the same vpn software... meaning we have a nortel client, firewall 1 ( i think) , fsecure etc..   My questions is, is it feasable or possible to let al lthe vpn connections run thru one machine as a vpn gateway, that routes according to where you wanna go to different tun devices, one for each client we have? and the next question. Since we have a few clients they all , well mostly) are pretty big and hav private ip addressing, yet some of them have the same range, hence client a uses 192.168.X.X and client b uses 192.168.X.X  how could i still route the correct packages to the correct client? The point of all this is that our projects mostly always involve the same people!
 but sometimes not and i dont wanna install ALL the vpn clients on all our computers...
So basically i need a machine that has severall tun devices, routes according to what packages come (oh yea nat needs to be done too but i think that can be done), establishes connections with the different VPNs , kinda like on demand dial and a way to differenciate 2 clients with the same iprange (private). <-- with that one i am stunned so far.

any comments, suggestions are more then welcome.

thanks

//Florian