User Manual

VCom Inc.
AP5857 Manual; ml_ap5857_08 (Oct 2005)
Approved: R.B.
34
7.0 IP ADDRESSES, NETMASK, ETC
7.1 IP Addressing
An IP address is a 32-bit value, divided into four octets of eight bits each. The standard representation is four
decimal numbers (in the range of 0...255), divided by dots.
Example: 192.2.1.123
This is called decimal-dot notation.
The IP address is divided into two parts: a network and a host part. To support different needs,
three “network classes“ have been defined. Depending on the network class, the last one, two or three bytes
define the host, while the remaining part defines the network.
In the following text, ‘x’ stands for the host part of the IP address:
Class A network
IP address 1.x.x.x to 127.x.x.x
Only 127 different networks of this class exist. These have a very large number of potential connected
devices (up to 16777216).
Example: 10.0.0.1, (network 10, host 0.0.1)
Class B network
IP address 128.0.x.x to 191.255.x.x
These networks are used for large company networks. Every network can consist of up to 65534 devices.
Example: 172.1.3.2 (network 172.1, host 3.2)
Class C network
IP address 192.0.0.x to 223.255.255.x
These network addresses are most common. Most smaller companies’ networks are class C networks.
These networks can consist of a maximum number of 254 hosts.
Example: 192.7.1.9 (network 192.7.1, host 9)
Class D network
IP address 224.x.x.x to 239.x.x.x
These addresses are used as multicast addresses.
Example: 224.7.1.9 (network 224, host 7.1.9)
Class E network
IP address 240.x.x.x to 254.x.x.x
These addresses are reserved.