Hello listmates, One of the most widespread security protocols is IPSec, but many of us have found that the number of knobs and settings and switches gets really overwhelming. I was in that boat as well, so I dove in and wrote a paper that covers IPSec at the protocol level. It doesn't cover things like Key Exchange yet (that's the *next* paper), but it's got a lot of detail that should be comforting to any TCP/IP geeks. Unixwiz.net Tech Tip: An Illustrated Guide to IPSec http://www.unixwiz.net/techtips/iguide-ipsec.html It's amazing how much one learns by writing about it... Steve -- Stephen J Friedl | Security Consultant | UNIX Wizard | +1 714 544-6561 www.unixwiz.net | Tustin, Calif. USA | Microsoft MVP | steve@xxxxxxxxxxx