Editing IPv4 (section)

===Address representations===
IPv4 addresses may be represented in any notation expressing a 32-bit integer value. They are most often written in [[dot-decimal notation]], which consists of four [[Octet (computing)|octet]]s of the address expressed individually in [[decimal]] numbers and separated by [[Full stop|periods]].

For example, the quad-dotted IP address in the illustration ({{IPaddr|172.16.254.1}}) represents the 32-bit [[decimal]] number 2886794753, which in [[hexadecimal]] format is 0xAC10FE01.

[[CIDR notation]] combines the address with its routing prefix in a compact format, in which the address is followed by a slash character (/) and the count of leading consecutive ''1'' bits in the routing prefix (subnet mask).

Other address representations were in common use when [[classful network]]ing was practiced. For example, the [[loopback]] address {{IPaddr|127.0.0.1}} was commonly written as {{IPaddr|127.1}}, given that it belongs to a class-A network with eight bits for the network mask and 24 bits for the host number. When fewer than four numbers were specified in the address in dotted notation, the last value was treated as an integer of as many bytes as are required to fill out the address to four octets. Thus, the address {{IPaddr|127.65530}} is equivalent to {{IPaddr|127.0.255.250}}.