Network News Transfer Protocol

from Wikipedia, the free encyclopedia
NNTP in the TCP / IP protocol stack :
application NNTP
transport TCP
Internet IP ( IPv4 , IPv6 )
Network access Ethernet Token
bus 		Token
ring 		FDDI ...

NNTP ( N etwork N ews T ransfer P rotocol ) is a transmission protocol for messages in newsgroups . It is used on Usenet . Its specifications were set out in RFC 977 (February 1986). Some extensions to the standard protocol were recorded in RFC 2980 (October 2000). In October 2006, RFC 3977 was published, which replaces or extends the two predecessors. The message format is defined in RFC 5536 (November 2009). The IANA has assigned TCP port 119 to the protocol .

NNTP is text-based and provides alternating requests from the client and subsequent responses from the server. These responses contain a first line with a numerical status code - a three-digit integer that informs about the success of the command - and further information, depending on the request. In some cases additional lines follow, always ending with a line with a single period.

The URL of an NNTP discussion forum or news page has the following structure: 

nntp://<host>:<port>/<newsgroup-name>/<article-number>

Commands ( RFC 3977 )

The original specification from 1986 already defines a sufficient number of commands to enable communication between server and client. This section introduces the most important commands.

  • HELP : lists the supported commands.
  • LIST : returns the names of the newsgroups available to the user , one per line.
  • GROUP : lets the user choose a new current group.
  • ARTICLE : requests an article, either via its number in the currently set group, or via its message ID .
  • POST : enables a new article to be submitted to the server.

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