Inventorying your routers' serial numbers is an important activity that every network administrator needs to be able to do -- both to keep track of what you have and to properly register for support and maintenance from Cisco Systems. How do you collect these numbers without physically going to each and every router in your organization? Here's how to determine those serial numbers remotely.

Did you know your Cisco router could send you an e-mail? Until recently, I would have said that it wasn't possible, but today, I'll show you how to do it. And we won't stop there: I'll tell you where to find some other scripts that you can use on your Cisco router.

While you may not have a network as large or as critical as YouTube to manage, unexpected network downtime or lost network traffic is never a good thing. That's why you should understand what a black hole route is, how it can help you -- and how it could hurt you.

Once you're ready to make the jump to a more sophisticated switch, what do you need to know? Let's answer some of the most frequently asked questions and explore the basic configuration of Cisco IOS switches.

With a simulator, there are always missing commands and programming errors, and it can never really be as complete as the real IOS. However, because an emulator runs the IOS, you get every feature that the real IOS has.

All Cisco routers have two special types of lines, and many Cisco routers have a third. What are these lines, and how do you configure them? These are things that every network admin should know.

A TechRepublic reader recently e-mailed me to ask about limiting the bandwidth on a Cisco Catalyst switch port. In fact, there are a number of uses for this configuration. Let's take a closer look.

One way to boost network security is to use Cisco's Port Security feature to lock down switch ports. Learn the basics of port security, and find out how to configure this feature.

When working with the Cisco IOS, it’s very important to know your TCP and UDP port numbers. This is especially true when creating IOS access control lists (ACLs). Let’s take a closer look. What’s a port number? Most of you likely know what port numbers are, but here’s a brief overview just in case: Port ...

While recently talking with a fellow network admin, I learned about Nipper. While there are many tools available to perform security audits of network devices, Nipper is unique. Let me show you why. What is Nipper? Short for Network Infrastructure Parser, Nipper is an open source network devices security auditing tool. One benefit of being ...