Identification Protocol (RFC1413)
Original Publication Date: 1993-Feb-01
Included in the Prior Art Database: 2000-Sep-12
Internet Society Requests For Comment (RFCs)
The Identification Protocol (a.k.a., "ident", a.k.a., "the Ident Protocol") provides a means to determine the identity of a user of a particular TCP connection. Given a TCP port number pair, it returns a character string which identifies the owner of that connection on the server's system.
Network Working Group M. St. Johns
Request for Comments: 1413 US Department of Defense
Obsoletes: 931 February 1993
Status of this Memo
This RFC specifies an IAB standards track protocol for the Internet
community, and requests discussion and suggestions for improvements.
Please refer to the current edition of the "IAB Official Protocol
Standards" for the standardization state and status of this protocol.
Distribution of this memo is unlimited.
The Identification Protocol (a.k.a., "ident", a.k.a., "the Ident
Protocol") provides a means to determine the identity of a user of a
particular TCP connection. Given a TCP port number pair, it returns
a character string which identifies the owner of that connection on
the server's system.
The Identification Protocol was formerly called the Authentication
Server Protocol. It has been renamed to better reflect its function.
This document is a product of the TCP Client Identity Protocol
Working Group of the Internet Engineering Task Force (IETF).
This is a connection based application on TCP. A server listens for
TCP connections on TCP port 113 (decimal). Once a connection is
established, the server reads a line of data which specifies the
connection of interest. If it exists, the system dependent user
identifier of the connection of interest is sent as the reply. The
server may then either shut the connection down or it may continue to
read/respond to multiple queries.
The server should close the connection down after a configurable
amount of time with no queries - a 60-180 second idle timeout is
recommended. The client may close the connection down at any time;
however to allow for network delays the client should wait at least
30 seconds (or longer) after a query before abandoning the query and
closing the connection.
Queries are permitted only for fully specified connections. The
query contains the local/foreign port pair -- the local/foreign
address pair used to fully specify the connection is taken from the
local and foreign address of query connection. This means a user on
address A may only query the server on address B about connections
between A and B.
4. QUERY/RESPONSE FORMAT
The server accepts simple text query requests of the form:
the "ident" server is running) system, and
TCP port (decimal) on the source (client) system.
N.B - If a client on host A wants to ask a server on host B about a
connection specified locally (on the client's machine) as 23, 6191
(an inbound TELNET connection), the client must actually ask about
6191, 23 - which is how the connection would be specified on...