In the Internet addressing architecture, the Internet Engineering Task Force (IETF) and the Internet Assigned Numbers Authority (IANA) have reserved various Internet Protocol (IP) addresses for special purposes. IPv4 IPv4 designates special usage or applications for various addresses or address blocks: IPv6 IPv6 assigns special uses or applications for various IP addresses: See also Bogon filtering Martian packet Classless Inter-Domain Routing (CIDR) References External links IANA IPv4 Special-Purpose Address Registry IANA IPv6 Special-Purpose Address Registry IP addresses