Junos® OS For Dummies®, 2nd Edition

Chapter 17

Operating and Troubleshooting Your Network

In This Chapter

• Using cause identification to find out what went wrong
• Controlling change to minimize risk
• Avoiding congestion by using Traffic Engineering
• Troubleshooting issues within your network

When networks were new, they broke all the time. But when they did break, the problem was easy to find and usually could be fixed quickly. Today, networks don't really break: They get “sick.” The network is still functioning, but parts of it are not doing what they are supposed to. Often, the root problem is difficult to isolate, and the fix may not work in all cases at all times.

Even the definition of just what a network is has changed over time. Everything is connected; we know that. So instead of fretting about what's a network or Internet or subnet, you can just say, “A network is all of the servers, clients, routers, switches, and other devices that I am responsible for.” Add them all up, and you have the global public Internet.

In this chapter, we look at the things you can do when your network is not functioning as it should. We show you how to find the root cause of a problem (or problems) and minimize the risk to your network by making incremental and controlled changes. You see how congestion can be addressed with the process of Traffic Engineering. Along the way, we explore a series of general procedures that can be used to investigate troubles.