Discussion Questions

1. We're discussion LANs this week. This includes a variety of types of LANs, each specified by the IEEE 802.x standards. IEEE 802.3 is specific to Ethernet and is one of the most common standards you'll be working wtih.

In the first post, you will find a .zip file which contains the six segments of the 802.3 standard. Select a topic from the standard and start a thread about that topic. Do NOT choose a topic someone else has already started discussing. In addition to your topic discussion, reply to at least three other students' comments.

2. The differences between routers and switches are somewhat blurred. Switches traditionally have operated at Layer 2, while routers have operated at layer 3. Then there's hubs, repeaters, bridges, etc operating at (for the most part) Layer 1. Now, however, we're seeing "Layer 3" switches, routing switches, and other varieties of "switches" being used at nearly all layers (I've seen up to Layer 5) of the OSI.

This leads to a number of questions like:

Are switches replacing all other devices listed in this discussion?

Are they really still switches if they operate at other than Layer 2?

Can a switch really route?

Which is faster - a router or a switch?

3. This week we're looking at LANs and OSI Layer 3 (plus Layers 4-7!). One of the biggest issues is that there are only a limited number of public IP addresses (and we're actually out of them...) To combat this (and also for security purposes), most networks actually use "private" IP addresses - usually using "non-routing" numbers. For example, this university probably only has a couple of public IP addresses; however, there are hundreds of computers and other devices connected to the networks which have access to the Internet. SO... How can 100's of computers connect to the Internet if we only have one or two (or even 10) public/routable IP addresses? There are a number of solutions, the most common being Network Address Translation (NAT), proxy servers, etc.