Operation Manual

VigorSwitch P1280 User’s Guide
11
Each class has its own network range between the network identifier and host identifier in the
32 bits address. Each IP address comprises two parts: network identifier (address) and host
identifier (address). The former indicates the network where the addressed host resides, and
the latter indicates the individual host in the network which the address of host refers to. And
the host identifier must be unique in the same LAN. Here the term of IP address we used is
version 4, known as IPv4.
Network identifier Host identifier
32 bits
With the classful addressing, it divides IP address into three classes, class A, class B and class
C. The rest of IP addresses are for multicast and broadcast. The bit length of the network
prefix is the same as that of the subnet mask and is denoted as IP address/X, for example,
192.168.1.0/24. Each class has its address range described below.
Class A:
Address is less than 126.255.255.255. There are a total of 126 networks can be defined
because the address 0.0.0.0 is reserved for default route and 127.0.0.0/8 is reserved for
loopback function.
Class B:
IP address range between 128.0.0.0 and 191.255.255.255. Each class B network has a 16-bit
network prefix followed 16-bit host address. There are 16,384 (2^14)/16 networks able to be
defined with a maximum of 65534 (2^16 –2) hosts per network.
Class C:
IP address range between 192.0.0.0 and 223.255.255.255. Each class C network has a 24-bit
network prefix followed 8-bit host address. There are 2,097,152 (2^21)/24 networks able to
be defined with a maximum of 254 (2^8 –2) hosts per network.