Ingredients

With any recipe, you first need the ingredients in order to produce your culinary masterpiece. Before getting into specific hardware requirements, you may need to have a better grasp on the general functions of the equipment you'll be using to connect all the pieces.

Hubs, Switches, Routers, etc

repeaters -> hubs -> switches -> routers...

repeater... hubs...

layered architecture.

• Physical (lowest) layer
  

  • HUBS operate at the physical layer. It's a multi-port repeater. Gets data/signal from one port, amplifies it and sends out on

    all other ports.</li>

• Data link layer
  

  • SWITCHES operate at the Data Link layer and use MAC addressses and one of several different data link protocols. Most common today is

    Ethernet. (Token rings are an alternative protocol.)
    
    Ethernet: Everyone talks at once. If more than one system talks at the same time there's a "collision". So the systems go into a "backoff" where both parties stop talking, wait random amounts of time and retry. The number of computers participating in the conversation and can hear each other is referred to as the "collision domain".
    
    

    • NIC = Network Interface Card
      MAC = Machine Access Code
      ARP = Address Request Protocol: IP addresses resolve to MAC addresses
      RARP = Reverse Address Request Protocol: versy-vicey.
      

    
    Switches keep ARP tables. Based on a MAC address.
    
    

  • Logical AND bitmask w/ IP address to get network address. If two different machines match, they're on the same NETWORK SEGMENT.

    Machines on same network segment need no routers.
    
    Switches maintain ARP tables which map MAC addresses with corresponding ports.

• Network layer
  

  • 
    ROUTERS operate at the the Network layer, and use IP addressing.

CROSS-OVER CABLES:

Category 5 (CAT-5) Ethernet cables: 8 wires. In 100 MB ethernet 4 are in use 2 for send 2 for receive. Send/Receive are swapped in an crossover cable. A switch does this internally.

If you don't have a router but have a spare old computer sitting around, you can turn it into a Coyote Linux Router.

Boot the server, and tell it to

• install to the hard disk
• Language: English (Default)
• Location: United States (Default)
• Keyboard: American English (Default)

It does the hardware detect, finds the CD-ROM, then scans it.

DMZ has no firewall...