tables to determine which of its interfaces it will use to send the data, in order for it to reach its destination network. In the example, the router determines that it should send the data from network A to network B, from its interface, with address B5. Before actually sending the data out interface B5, the router would encapsulate the data in the appropriate data link frame. A router’s attachment to a network is called an interface; it may also be referred to as a port. In IP routing, each interface must have a separate, unique network (or subnetwork) address After you have determined the addressing scheme for a network, you must choose the method for assigning addresses to hosts. There are essentially two methods for assigning IP addresses - static addressing and dynamic addressing. Regardless of which addressing scheme you use, no two interfaces can have the same IP address. Static Addressing If you assign IP addresses statically, you must go to each individual device and configure it with an IP address. This method requires you to keep very meticulous records, because problems can occur on the network if you use duplicate IP addresses. Some operating systems, such as Windows 95 and Windows NT, send an ARP request to check for a duplicate IP address when they attempt to initialize TCP/IP. If they discover a duplicate, the operating systems will not initialize TCP/IP and will generate an error message. Record keeping is important too, because not all operating systems identify duplicate IP addresses. Dynamic Addressing There are a few different methods that you can use to assign IP addresses dynamically. Examples of these are: Reverse Address Resolution Protocol (RARP) Reverse address resolution protocol (RARP) binds MAC addresses to IP addresses. This binding allows some network devices to encapsulate data before sending them out on the network. A network device such as a diskless workstation might know its MAC address, but...
