Editing Private network (section)

==Private IPv4 addresses==
The [[Internet Engineering Task Force]] (IETF) has directed the [[Internet Assigned Numbers Authority]] (IANA) to [[Reserved IP addresses|reserve]] the following IPv4 address ranges for private networks:<ref name=rfc1918 />{{Rp|page=4}}
{{Table alignment}}
{| class="wikitable sortable col1left col7left defaultright"
! RFC 1918 name !! IP address range !! Number of addresses
! Largest [[CIDR]] block (subnet mask) || Host ID size || Mask bits
! ''[[Classful]]'' description{{refn|group="Note"|[[Classful addressing]] is obsolete and has not been used in the Internet since the implementation of [[Classless Inter-Domain Routing]] (CIDR), starting in 1993.  For example, while {{IPaddr|10.0.0.0|8}} was a single class A network, it is common for organizations to divide it into smaller {{IPaddr||16}} or {{IPaddr||24}} networks. Contrary to a common misconception, a {{IPaddr||16}} [[subnet]] of a class A network is not referred to as a class B network. Likewise, a {{IPaddr||24}} subnet of a class A or B network is not referred to as a class C network.  The class is determined by the first three bits of the prefix.<ref>{{cite book|last=Forouzan|first=Behrouz|title=Data Communications and Networking|year=2013|publisher=McGraw Hill|location= New York|isbn= 978-0-07-337622-6|pages= 530–31}}</ref>}}
|-
| 24-bit block || 10.0.0.0 – 10.255.255.255 ||{{gaps|16|777|216}} || 10.0.0.0/8 (255.0.0.0) || 24&nbsp;bits || 8&nbsp;bits || single class A network
|-
| 20-bit block || 172.16.0.0 – 172.31.255.255 || {{gaps|1|048|576}} || 172.16.0.0/12 (255.240.0.0) || 20&nbsp;bits || 12&nbsp;bits || 16 contiguous class B networks
|-
| 16-bit block || 192.168.0.0 – 192.168.255.255 || {{gaps|65|536}} || 192.168.0.0/16 (255.255.0.0) || 16&nbsp;bits || 16&nbsp;bits || 256 contiguous class C networks
|}

In practice, it is common to subdivide these ranges into smaller [[subnet]]s.