Prelude: As far as I understand, a VPN is a (un)secured tunnel over a end-to-end connection (e.g. TCP/IP) that serves sort of like a gateway, passing traffic between the two ends transparently. Please correct me if i'm wrong here.

I've read about people (ok, black hats) using reverse-connecting shellcode to bypass firewalls when attacking sites. Wouldn't it be simpler to run a server, local only, and have a generic reverse connecting VPN system set up? This would work like so:

normal VPN:

server listening 0<------- client connects

server's lan <---VPN tunnel---> client's lan

reverse VPN:

server attempting to connect ------------->

server attempting to connect ------------->

server connecting -------->0 client listening

server's lan <---VPN tunnel---> client's lan

I don't know how easily this could be implemented because I don't know of any open source VPNs.

Thoughts?

Odd, edit post wouldn't accept my password.

Edit: this would also give the added bonus of being able to access the server's normal local-only services or the same services on another server in its lan.

wtf? why do you want to reverse connect why not just make the client the server?

vpn is pretty secure stop bashing it. it uses encryption and does a good job of being transparent.

the only insecurity is that one of the computer in the route from ur comp to the server (have tracert handy).

I wasn't intentionally bashing it. I meant that there might be versions of it around that aren't secure.

I see what you mean about make the server the client. Anyone know of open source VPN systems that I can mess with?

www.openswan.org (http://www.openswan.org)

check freshmeat (http://freshmeat.net/search/?q=VPN&section=projects&Go.x=15&Go.y=10)

[This message has been edited by cense (edited 12-20-2004).]

Thanks, I'll look into it.