i am an Debianer ,so like linux very much. i use linux for a either long or short time. Now i use Debian. but i don't how to use it userful for me,special in Lan manage. i know a few tools ,eg: ntop, IDS,but in my work ,this may be useless. i want some example for the office and Lan manage by using Debian you can introduce Lan security tools to me. thx -- 其实阿峰不坏