Perl for Web Site Management

Network Troubleshooting

One of the really cool things about the Internet is the way you, or anyone, can see how your traffic is being routed across the Net, and what’s happening to it along the way. This comes in very handy when you’re experiencing some sort of problem connecting to another site. With just a few seconds of research, you can often tell exactly where the problem lies, and this in turn can tell you if it’s something you need to fix yourself, something you need to complain to somebody else about, or something that’s essentially out of your control. It also comes in very handy for evaluating the quality of the explanations you get when you bug your ISP about network outages, which in turn can be an important factor in deciding where to host your web site.

ping and traceroute

The first network utilities we’re going to talk about are the ping and traceroute commands. These utilities let you probe a TCP/IP network (like the Internet) to see where your data packets are going, how long it’s taking them to get there, and whether any of them are getting lost along the way. (See Packet-Switching 101 if these concepts are new to you.)

Packet-Switching 101

The Internet runs on TCP/IP, 1776 which stands, if you’re into acronym expansion, for Transmission Control Protocol/Internet Protocol. TCP/IP is a form of networking based on packet switching. I’ve assumed in this book that you’ve been using the Internet and making web pages for a while, so you’ve probably already picked up ...