How Can You Screw up a Network?

aztektum asks: "Like a lot of Slashdot readers, I have setup my own home network. It isn't tricked out with all the fanciest hardware, but I do have a switch, BSD based firewall, I have configured e-mail (again on BSD), NFS and Samba, as well as remote access services like SSH and FTP. Now my line of work isn't networking or computer related at all. This is a personal hobby and a fairly new one for me (relatively speaking compared to others). I'm looking to learn more about managing problems with networks, but have no idea where to start. With such a small setup and only supporting two users (myself and a roommate) this isn't exactly enterprise level with enterprise level ups and downs. What are some ways I can screw up my network to troubleshoot problems and gain some insight? Also, what are some reference materials that you have found to be educational with relation to network administration?"

Troubleshoot?

[Anonymous Coward]

What are some ways I can screw up my network to troubleshoot problems and gain some insight?

Well, if you're the one who deliberately screwed it up in the first place you'd pretty much have to be an Alzheimer's victim for it to require "troubleshooting".

Real advice: Ask someone else to screw it up for you.

Another way: play packet WTF

[dubl-u]

Another great way to learn about your network is to install a packet sniffer like Ethereal [ethereal.com]. Capture some packets, pick a random one, and try to figure out what the hell it's for.

For the advanced version of the game, do something specific (bring a DHCP machine up; do an FTP transfer; surf a web site) and write down what you think goes on on the network. Then capture the packets and see how close you can get.

By learning what a network looks like when it's working normally, you'll have a much better chance of figuring out problems when they happen.