User's Manual

SPEEDLAN TM

In fact, IP defines five classes:

• Class A addresses use 8 bits (1 octet) for the network portion and 24 bits (3 octets) for the node

(or host) section of the address. This provides up to 128 networks with 16.7 million nodes for each

network.

• First byte is assigned as network address

• Remaining bytes used for node addresses

• Format: network, node, node, node

• In IP address 49.22.102.70, “49” is network address and “22.102.70” is the node

address – all machines on this network have the “49” network address assigned to them

• Maximum of 2

or 16,777,216 nodes

• Class B addresses use 16 bits (two octets) for the network portion and 16 bits for the node (or

host) section of the address. This provides up to 16, 384 networks with 64,534 nodes for each

network.

• First two bytes are assigned as network address

• Remaining bytes used for node addresses

• Format: network, network, node, node

• In IP address 130.57.30.56, “130.57” is the network address, and “30.56” is the

node address

• Maximum of 216 or a total of 65,534 nodes

• Class C addresses use 24 bits (3 octets) for the network portion and 8 bits (two octets) for the

node (or host) section of the address. This provides 16.7 million networks with 256 nodes for each

network.

• First three bytes are assigned as network address

• Remaining byte used for node address

• Format: network, network, network, node

• In IP address 198.21.74.102, “198.21.74” is the network address, and “102” is the

node address

• Maximum of 28 or 254 node addresses

• Class D

• Range is 224.0.0.0 to 239.255.255.255

• Used for multicast packets (i.e., host sends out router discovery packets to learn all of the

routers on the network)

• Class E

• Range is 240.0.0.0 to 255.255.255.255

• Reserved for future use

Note: Class D & E should NOT be assigned to net assignment of IP addresses. In addition, the

first octet, 127, is reserved.In each network definition, the first node number (i.e., “0”) is used to

define the network, as well as the last number (i.e., “255”). The last number is known as the

broadcast address.

Public IP addresses can be obtained from the following address:

Network Solutions

InterNIC Registration Services

505 Huntmar Park Drive

Herndon, VA 22070

hostmaster@internic.net