questions about my topology (lab)

[Kenmasters]

Hello,

Over the past year studying network theory, I've never been able to practice. That's why I decided to make a laboratory to practice what I learned.

Here is the topology that I just made with Visio:

I have some questions:

How to choose between fast ethernet and Gigabyte cables ? Where is important to use GB?

Does Snort and Nagios are well placed (I have never used, I just know what's their goal?

Have you any ideas for improvement my topology? should I use another router to improve this network?

What do you recommend for the firewall? I thought about pfSense.

sorry for my english :/

[rendrag]

Unless you're going to be moving a lot of files across that network, 10/100 should be fine, but if you're going to be doing structured cabling (running it through walls and such), then don't bother with 10/100 and do as fast as you can afford.

As far as optimal placement, so long as you're using switches and not hubs, your placement is fine (given the quantity of devices), and there would be no real benefit to putting in any more routing devices.