NAT Port Mapping Protocol (NAT-PMP) is a

network protocol A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any variation of a physical quantity. The protocol defines the rules, syntax, semantics, and synchronization of ...

for establishing

network address translation Network address translation (NAT) is a method of mapping an IP address space into another by modifying network address information in the IP header of packets while they are in transit across a traffic Router (computing), routing device. The te ...

(NAT) settings and

port forwarding In computer networking, port forwarding or port mapping is an application of network address translation (NAT) that redirects a communication request from one address and port number combination to another while the packets are traversing a netwo ...

configurations automatically without user effort. The protocol automatically determines the external

IPv4 Internet Protocol version 4 (IPv4) is the first version of the Internet Protocol (IP) as a standalone specification. It is one of the core protocols of standards-based internetworking methods in the Internet and other packet-switched networks. ...

address of a NAT gateway, and provides means for an application to communicate the parameters for communication to peers.

Apple An apple is a round, edible fruit produced by an apple tree (''Malus'' spp.). Fruit trees of the orchard or domestic apple (''Malus domestica''), the most widely grown in the genus, are agriculture, cultivated worldwide. The tree originated ...

introduced NAT-PMP in 2005 by as part of the Bonjour specification, as an alternative to the more common ISO Standard

Internet Gateway Device Protocol Internet Gateway Device (UPnP IGD) Control Protocol is a protocol based on Universal Plug and Play, UPnP for mapping Port (computer networking), ports in network address translation (NAT) setups, supported by some NAT-enabled Router (computing), ...

implemented in many NAT routers. The protocol was published as an informational

Request for Comments A Request for Comments (RFC) is a publication in a series from the principal technical development and standards-setting bodies for the Internet, most prominently the Internet Engineering Task Force (IETF). An RFC is authored by individuals or ...

(RFC) by the

Internet Engineering Task Force The Internet Engineering Task Force (IETF) is a standards organization for the Internet standard, Internet and is responsible for the technical standards that make up the Internet protocol suite (TCP/IP). It has no formal membership roster ...

(IETF) in RFC 6886. NAT-PMP runs over the

User Datagram Protocol In computer networking, the User Datagram Protocol (UDP) is one of the core communication protocols of the Internet protocol suite used to send messages (transported as datagrams in Network packet, packets) to other hosts on an Internet Protoco ...

(UDP) and uses

port number In computer networking, a port is a communication endpoint. At the software level within an operating system, a port is a logical construct that identifies a specific process or a type of network service. A port is uniquely identified by a numbe ...

5351 on the server, whilst port 5350 is used on the client, as per spec. It has no built-in

authentication Authentication (from ''authentikos'', "real, genuine", from αὐθέντης ''authentes'', "author") is the act of proving an Logical assertion, assertion, such as the Digital identity, identity of a computer system user. In contrast with iden ...

mechanisms because forwarding a port typically does not allow any activity that could not also be achieved using

STUN STUN (Session Traversal Utilities for NAT; originally Simple Traversal of User Datagram Protocol (UDP) through Network Address Translators) is a standardized set of methods, including a network protocol, for traversal of network address transl ...

methods. The benefit of NAT-PMP over STUN is that it does not require a STUN server and a NAT-PMP mapping has a known expiration time, allowing the application to avoid sending inefficient keep-alive packets. NAT-PMP is the predecessor of the

Port Control Protocol Port Control Protocol (PCP) is a computer networking protocol that allows hosts on IPv4 or IPv6 networks to control how the incoming IPv4 or IPv6 packets are translated and forwarded by an upstream router that performs network address translat ...

(PCP).

References

External links

Port Mapping Protocols Overview and Comparison 2024 — About UPnP IGD & PCP/NAT-PMP
Apple Inc. services Network protocols Network address translation {{Apple-stub

See also

References

External links