Script to detect common network problems
In case you have a networking problem:
There exists a bash script on collectNWData ‹berblick / Overview | collectNWData.sh which analyzes a Linux box for common wired and wireless network configuration problems and gives hints how to solve the problem. If it's still not possible to fix the problem the script collects a lof of network configuration information in a file which can be posted on a nopaste web site and helps everybody familiar in Linux networking to fix the networking problem very quickly.
It's used right now by the German Linux community (more than 9000 downloads already) and I'm sure it's also helpful in this community (web pages written in English and German) - fix a network problem on your own and to provide networking info for folks who can help you to fix problems.