Emerson Liebert iCOM Training And Service Manual page 198

iCOM
Control Training and Service Manual
Understanding IP Addressing: Every computer that communicates over the
Internet is assigned an IP address that uniquely identifies the device and
distinguishes it from other computers on the Internet. An IP address consists of 32
bits, often shown as 4 octets of numbers from 0-255 represented in decimal form
instead of binary form. For example, the IP address 168.212.226.204 in binary
form is: 10101000.11010100.11100010.11001100.
But it is easier for us to remember decimals than it is to remember binary
numbers, so we use decimals to represent the IP addresses when describing
them. However, the binary number is important because that will determine which
class of network the IP address belongs to. An IP address consists of two parts,
one identifying the network and one identifying the node, or host. The Class of the
address determines which part belongs to the network address and which part
belongs to the node address. All nodes on a given network share the same
network prefix but must have a unique host number.
Class A Network: Binary address start with 0, therefore the decimal number can
be anywhere from 1 to 126. The first 8 bits (the first octet) identify the network and
the remaining 24 bits indicate the host within the network. An example of a Class
A IP address is 102.168.212.226, where "102" identifies the network and
"168.212.226" identifies the host on that network.
Class B Network: Binary addresses start with 10, therefore the decimal number
can be anywhere from 128 to 191 (the number 127 is reserved for loopback and is
used for internal testing on the local machine). The first 16 bits (the first two
octets) identify the network and the remaining 16 bits indicate the host within the
network. An example of a Class B IP address is 168.212.226.204 where
"168.212" identifies the network and "226.204" identifies the host on that network.
Class C Network: Binary addresses start with 110, therefore the decimal number
can be anywhere from 192 to 223. The first 24 bits (the first three octets) identify
the network and the remaining 8 bits indicate the host within the network. An
example of a Class C IP address is 200.168.212.226 where "200.168.212"
identifies the network and "226" identifies the host on that network.
Class D Network: Binary addresses start with 1110, therefore the decimal number
can be anywhere from 224 to 239. Class D networks are used to support
multicasting.
Class E Network: Binary addresses start with 1111, therefore the decimal number
can be anywhere from 240 to 255. Class E networks are used for
experimentation. They have never been documented or utilized in a standard
way.
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