Netgear PS111W User Manual download pdf (Page 93)

NetGear Print Server Manual

Class B addresses can have up to 65,354 hosts on a network. Class B addresses use a 16-bit network

number and a 16-bit node number. Class B addresses are in this range:

128.1.x.x to 191.254.x.x. 

Class C addresses can have 254 hosts on a network. Class C addresses use 24 bits for the network

address and 8 bits for the node. They are in this range:

192.0.1.x to 223.255.254.x. 

Class D addresses are used for multicasts (messages sent to many hosts). Class D addresses are in this

range:

224.0.0.0 to 239.255.255.255. 

Class E addresses are for experimental use.

This addressing structure allows IP to uniquely identify each physical network and each node on each

physical network.

For each unique value of the network portion of the address, the base address of the range (host

address of all zeros) is known as the network address and is not usually assigned to a host. Also, the

top address of the range (host address of all ones) is not assigned but is used as the broadcast address

for sending a packet simultaneously to all hosts with the same network address.

Netmask

In each of the above address classes, the size of the two parts (network address and host address) is

implied by the class. This partitioning scheme can also be expressed by a netmask associated with the

IP address. A netmask is a 32-bit quantity that, when logically ANDed with an IP address, yields the

network address. For instance, the netmasks for Class A, B, and C addresses are 255.0.0.0, 255.255.0.0,

and 255.255.255.0, respectively.

For example, the address 192.168.170.237 is a Class C IP address whose network portion is the upper

24 bits. When ANDed with the Class C netmask, as shown here, only the network portion of the

address remains:

11000000 10101000 10101010 11101101 (192.168.170.237)

ANDed with:

11111111 11111111 11111111 00000000 (255.255.255.0)

Equals:

11000000 10101000 10101010 00000000 (192.168.170.0)

As a shorter alternative to dotted-decimal notation, the netmask may also be expressed in terms of the

number of ones from the left. This number is appended to the IP address, following a backward slash

( / ), as "/n." In the example, the address could be written as 192.168.170.237/24, indicating that the

netmask is 24 ones followed by 8 zeros.

1 2 ... 88 89 90 91 92 93 94 95 96 97 98 ... 105 106

No comments

Netgear PS111W User Manual Page 93