Perform various subnet network calculations given any combination of IP-address, subnet mask, or subnet bits.
While subnet masks are often represented in dot-decimal form, their use becomes clearer in binary.
Subnet masks consist of 32 bits, building a block of 1s followed by a block of 0s.
The 1s designate that part of the address as being part of the network portion and the 0s designate that part as being part of the host address.
Subnet masks can also be expressed in a shorter form, known as Classless Inter-Domain Routing (CIDR) notation, which gives the network number followed by a slash / and the number of 1 bits in the binary notation of the netmask (i.e. the number of relevant bits in the network number).
Subnet mask: 255.255.255.0
Bits: 11111111 11111111 11111111 00000000