= IP = '''Internet Protocol''' ('''IP''') is a foundational network protocol for routing across networks. Machines are assigned an '''Internet Protocol Address''' ('''IP address''') to which packets are addressed. <> ---- == Addresses == An IP address is a unique 32-bit or 128-bit number, for IPv4 and IPv6 respectively. Addresses can either be static or dynamically assigned. The predominant method for assigning dynamic addresses is [[Protocols/DHCP|DHCP]]. === Reserved Addresses === A set of addresses are reserved for local networking: ||'''IP Block''' ||'''IP Range''' ||'''Reserved for''' || ||127.0.0.0/8 ||127.0.0.0 - 127.255.255.255 ||Loopback || ||10.0.0.0/8 ||10.0.0.0 - 10.255.255.255 ||Local network || ||172.16.0.0/12 ||172.16.0.0 - 172.31.255.255 ||Local network || ||192.0.0.0/24 ||192.0.0.0 - 192.0.0.255 ||Local network || ||192.168.0.0/16 ||192.168.0.0 - 192.168.255.255 ||Local network || ||::1/128 ||::1 (yes, just one address) ||Loopback || ||fc00::/7 ||fc00:: - fdff:ffff:ffff:ffff:ffff:ffff:ffff:ffff ||Local network || There are also a number of reservations for infrastructure and future use. The remainder are mapped to the public internet. ---- == Networks == Most networks are '''Local Area Networks''' ('''LAN'''). A LAN should restrict itself to the set of addresses reserved for local addressing, but there is no reason for local addresses to be globally unique. A '''gateway''' stands between the LAN and the '''Wide Area Network''' ('''WAN'''). The '''Internet Assigned Numbers Authority''' ('''IANA''') manages the assignment of addresses in this space. ---- == Design == Apart from the standardization of addresses, IP also lays out how packets should be formed and routed. IP packets are assumed to be unreliable, for reasons including data corruption, out-of-order delivery, and disappearance. This is only mitigated by a checksum included in the IP packet. If any relaying node finds fault in a checksum, however, the packet is discarded without notification. All issues of the IP network are expected to be solved in higher-level protocols. ---- CategoryRicottone