Networks

Networks

1. Topologies

   • Bus Topology
     • Cheap to install
     • A single cable that runs through the network.
     • High chance of catastrophic failure
     • Lots of collisions
     • Slows down as more computers are added
   • Star Topology
     • All computers are connected to a central switch
     • Low chance of failure
     • No collisions (fast)
     • Easy to add new computers
     • Expensive
     • Depends on a switch
   • Ring Topology
     • Computers are connected to each other in a ring
     • Cheap to install
     • No collisions (fast)
     • High chance of catastrophic failure
     • Difficult to expand
   • Yellow=advantages pink=disadvantages

2. LAN

   • Local Area Network
   • Spans in a single geographical location or organisation

3. Advantages

   • All files can be easliy accessed by all computers in the network.
   • The same login and password can be used on any computer.
   • To install something on the network, you can do it all at the same time.
   • The same resources (print, internet and email) can be used on all computers.

4. Disadvantages

   • Networks can be very expensive to set up.
   • If a computer gets a virus, it is likely that all computers will get it as well.
     • To fix it, you have to go through each computer individually.
   • If it is hacked(which is quite easy to do) the hacker can access every file on all computers.

5. WAN

   • Wide Area Network
   • Spans a large geographical area,for multiple organisations
     • Often consists of multiple LANs networked together

6. IP Addresses

   • Measured in binary, in groups of 8. For example, 00100101,01010101,01110111,10101010 is 37.85.119.170
   • Unique value, assigned to every computer on a network to identify it.
   • Messages on a network have one and this is how computers know whether to keep a message or not
   • However, there are not enough to come up with a unique IP Address for every internet-connected device in the world.
     • We get round this by assigning an “external” IP address to each house or business, then “internal” IP addresses to the computers in that house or business.

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