There was a nice article in SYSAdm sometime last year -- I think June 97
issue. Check it.
On Thu, 5 Mar 1998 ccurtis @
> I realize this is a bit off-topic, but since the VPN topic just popped up
> I figured I'd ask ... at least it's not spam. ;-)
> I was wondering if anyone had a HOWTO pointer or some general ideas on
> how to create a VPN using Linux. Ideally, the system should encapsulate
> an IP packet (with a non-routable address) inside another packet as data,
> fully (128bit) encrypted, which would then be tunnelled to another Linux
> machine, to decrypt the packet and route it properly. I know Linux will
> do IP encapsulation (especially for the notebook users) but how would one
> go about implementing an encryption layer in there?
> Secondly, one of the key issues dealing with VPNs is authentication.
> Sadly, I'm not terribly well versed in the OSI models et al, and don't
> even know where to start in this respect. Does the TCP layer have an
> extra (or data) field that can store an auth-key, or would I have to use
> a modificied TCP stack? This system would use, of course, IPv4 ...
> unless, of course, IPv4 could encapsulate an IPv6 packet that can be
> authenticated against...
> Ideas, suggestions?