On both TCP/IP (Transmission Control Protocol/Internet Protocol) and IPX (Internet Packet eXchange) networks every address has a network portion and a node portion. The network portion identifies which segment the station, or node, is connected to. The node portion identifies the particular station, or computer, that is on that segment.
On IPX, two number sets, split in half by a colon, make up an address. Below is an example of what an IPX address looks like.
00004567: 006A7C11FB56
The first set of numbers (before the colon symbol) is an eight-digit, hexadecimal number that is either randomly assigned by an installation program or set manually by a network's administrator. The second number set (after the colon) is the twelve-digit, hexadecimal MAC (media access control) address assigned by the manufacturer to the network adaptor (usually an Ethernet card). A MAC address can be broken down further. Let's look at just the node portion of the above example.
006A7C
The first half of the MAC address is known as the prefix. In the above example 006A7C indicates the network adapters manufacturer.
11FB56
The second half of the MAC address is the actual serial number of the network adapter assigned at the factory.
In summary, the above address tells us that the machine in question is on segment 00004567 and is node 006A7C11FB56.
TCP/IP addresses are composed of four sets of three digit numbers that are separated by decimal points. The numbers in each octet range from one to 254. Below is an example of what an IP address looks like.
199.217.67.34
Which portion of an IP address contains the network address is determined by the address class and its' assigned subnet mask. A subnet mask is identical in its format to an IP address with the exception that it uses numbers ranging from zero to 255. Below is an example of what a subnet mask might look like.
255.255.255.0
If a subnet mask contains 255 in an octet position then the corresponding portion of the IP addresses is the network portion. Let's imagine that we are discussing a machine that has an IP address of 199.217.67.34 and has been assigned a submask of 255.255.255.0. Since the subnet mask has the number 255 in the first three octets this would mean that the machine's IP address can be looked at in the following manner.
199.217.67 = network portion
.34 = node address portion
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