What are some cool or useful server/networking tricks? [closed]

For example:

Setting up a server as an secure HTTP proxy to use in a filtered internet connection. Altering a computer's/network's DNS to reroute traffic.

What are some other fun and useful tricks you think we should all know about?

Solution 1:

Screen

(linux & OS X/macports)

It allows console users to run any number of text-based applications, interactive command shells, curses-based applications, text editors etc, within a single terminal.

I barely started using it fluently, thanks to a few online tutorials out there: http://news.softpedia.com/news/GNU-Screen-Tutorial-44274.shtml

Quick reference:

• Start a new session: #screen -S sessioname
• Ctrl+a d to detach
• List running sessions: #screen -ls
• Connect to running session: #screen -x sessioname

There are some Pros here who might want to add to this post their useful commands for screen.

Here's another useful tutorial

Solution 2:

Using your host file to send ad crap to localhost.

Solution 3:

anycast - we use it for our DNS.