# Net+ Certification



## ITechnician45 (Nov 21, 2005)

I am studying for the Net+ Certification using the "Exam Cram 2 Network+ 2nd Edition" book. My class is going through the book chapter by chapter and are currently on topologies. Now I know that the A+ Core Hardware Exam covered this but it was my weakpoint. I am looking, not only for resources, but experenced knowledge as well. We are studying 5 types of Network Topologies on the physical level bus, ring, star, mesh, and wireless. We also are studying hybrids. Any resources or just personal experiences with these topologies (troubleshooting, creating, configuring, etc.) will be greatly appreciated! Also, I am having issues with a wireless connection at my home. I am connecting to a neighbor's wireless router (per previous agreement between all 3 parties them, us, and the company). I am covering a distance of <100 and have a wirless NIC and antenna from ASUS already equipped for my PC. I am having issues with signal strength and would like any advice I could get on repeating the signal to strengthen my connection.


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## Cellus (Aug 31, 2006)

Think of the topologies as a graphical representation as to how nodes are laid out.

Keep in mind the difference between a _physical_ topology and a _logical_ topology. Physical is literally how each node is physically connected to each other. Logical is how they are, logically, connected. For example, Token Ring uses a logical ring but a physical star (uses token passing but all nodes connect to a central MAU).

A *Star* can be thought of as a "hub and spoke". Nodes connect to a central location which is the hub while the other nodes are the spokes. Useful for centralized management as every spoke has to go through the hub to reach another spoke. If a spoke fails, the network is still intact. If the hub fails, the spokes fail.
A *Ring* has each node connecting to adjacent nodes in the shape of a ring. Useful in cases like Token Ring with token passing (think a "talking stick").
A *Mesh* can be thought of as a web - nodes connect to several other nodes giving high redundancy with multiple communication paths.
A *Bus* can be thought of as a single path with terminators at both ends.
Hybrids are simply the adaption of two or more of the above topologies.
Wireless is a bit iffy, as it really isn't quite its own topology. Wireless is actually a technology that can be adapted as an alternative to a wired connection. It does have that "network architecture" bit in it where it radiates a blanket of coverage, but logically with APs connected to a wired connection you get one of the more traditional logical topologies.

You will be asked a question or two on FDDI - simply think of it as token ring with two rings where a second ring is used for "supervisory" messages and redundancy (if one part of one ring is severed it can jump on the second ring as failover).

In regards to your wireless problem, physical obstructions and electromagnetic interference can attenuate the signal, causing signal loss. Everything from walls to microwaves can interfere. See what you can do to remove those obstructions, or move your computer.


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