On Sun, 10 Jun 2001, Zachary Uram wrote: > what are layer 1 and layer 4 type devices? Do a search for "OSI model". http://www.lex-con.com/osimodel.htm is probably a good link (just did a quick search myself). This is BASIC knowledge for anyone in networking, very basic. They mention this in the first few chapters/classes of any major networking book. If you do not know it, it's time to start studying it. It might not make much practial use, but it makes for better communicating with others when you're describing problems. -- Mikael Abrahamsson email: swmike@swm.pp.se - [To unsubscribe, send mail to majordomo@lists.gnac.net with "unsubscribe firewalls" in the body of the message.]