Private IP Address Ranges

Address ranges below are reserved by IANA for private intranets, and not routable to the Internet. For additional information, see RFC 1918.

  • 10.0.0.0 ~ 10.255.255.255 (10.0.0.0/8 prefix)
  • 172.16.0.0 ~ 172.31.255.255 (172.16.0.0/12 prefix)
  • 192.168.0.0 ~ 192.168.255.255 (192.168.0.0/16 prefix)

Reserved and special use addresses

  • 0.0.0.0/8 - Current network (only valid as source address) RFC 1700
  • 127.0.0.0 is reserved for loopback and IPC on the localhost.
  • 127.0.0.1 ~ 127.255.255.254 (127.0.0.0/8) - loopback IP addresses (refers to self) RFC 5735
  • 192.0.0.0/24 - reserved (IANA) RFC 5735
  • 192.88.99.0/24 - IPv6 to IPv4 relay. RFC 3068
  • 198.18.0.0/15 - network benchmark tests. RFC 2544
  • 198.51.100.0/24 - TEST-NET-2. RFC 5737
  • 203.0.113.0/24 - TEST-NET-3. RFC 5737
  • 224.0.0.0 ~ 239.255.255.255 (224.0.0.0/4) reserved for multicast addresses. RFC 3171
  • 240.0.0.0/4 - reserved (former Class E network) RFC 1700
  • 255.255.255.255 is the limited broadcast address (limited to all other nodes on the LAN) RFC 919
  • 255 in any part of the IP is reserved for broadcast addressing
  • 0.0.0.0 in routing context means the default route (to "the rest of" the internet) RFC 1700
  • 0.0.0.0 in the context of firewalls means "all addresses of the local machine" RFC 1700