Now that you have become a self-proclaimed network performance expert, do you see things the same way? Look at the graphic in Figure 5.32. What questions come to mind right off the top of your head now? Where do you start looking? What is considered normal activity for this network? These questions should be easier to answer now because as you become a Sniffer Certified Professional and network analyst, you can see things in a different way. You look at networks differently from people who do not know what is going on in them; you look through the wire and see what could be hindering performance. It is our goal to have you finish this book and be able to answer that age-old question, Why is the network so slow?

Figure 5.32: A Redesigned Network After Good Performance Monitoring

After looking at this new design and the old one from Figure 5.1, let s look at what we did to increase performance with only your knowledge of networks, reading this book, common sense, and the Sniffer Pro analyzer. What performance gains did we get after performance monitoring, getting the application flows, analyzing the current infrastructure design, and putting forth some good, solid solutions? How about the following:

1. Now users do not have to cross a WAN link to get to the domain controller. They can log in on the local segment to which they are attached.

2. Since the domain controllers have to replicate information...