CertiGuide to Network+  9  Chapter 0101:  TCP/IP

I  Concepts & Terms Required - Chapter 0101 1 III  IP Address Details

TCP/IP network addressing has three building blocks. In effect, this means that any given network device has three unique identifiers, at successively higher levels of abstraction and “user-friendliness”. They are:

1. The physical address is the MAC (Media Access Control) address assigned to the NIC at manufacturing time. This is usually written in hex, for example 00-aa-00-62-c6-09. This is bound or given a translation to the IP address that is assigned to the device.
   
   
2. The IP address is a 32 bit binary number that indicates the network number and the unique client or host number on that network. It is typically written out as a series of 4 numbers, separated by periods, such as 199.97.31.1. This address is NOT fixed in the device when it is manufactured. Rather, it can be assigned (and re-assigned) by the network admin, or even by automated software programs on the network.
   
   These addresses are easier to remember than physical addresses, because the addresses of all hosts on a LAN tend to start with the same numbers.
   
   The Address Resolution Protocol (ARP) maps physical addresses to logical IP addresses.
   
   
3. 3. The host name or fully qualified domain name (FQDN), which is a human name given to the computer or device without having to remember something like 00001010000000000000000000000010 (10.0.0.2). (Domain names will be discussed later in this chapter) Domain names like www.CertiGuide.com are obviously the easiest to remember of all the identifier schemes. The Domain Naming System (DNS) maps domain names to logical IP addresses. If Base 2 math makes a much sense to you as a foreign language you do not understand, refer to Appendix B.

I  Concepts & Terms Required - Chapter 0101 1 III  IP Address Details