NETMASK

Knowing the class (A, B or C) of the network address, it's easy to split the network part and the host part of a given IP address:  44.134.177. 48 it's a class A network address 140.105. 28.160 it's a class B network address (but with subnetting!) 192. 41.  6. 20 it's a class C network address The standard way to specify it (with subnetting too) is using a further numeric field, called netmask the netmask (in binary format) is composed of as many 1s as the lenght (in bits) of the network (and subnet) part, followed of as many 0s as the lenght of the host part of the address: the two example netmasks, expressed in a 4-part, period delimited, decimal form are 255.255.252.0 and 255.255.255.224