Identification Protocol
RFC 1413
| Document | Type |
RFC - Proposed Standard
(February 1993; Errata)
Obsoletes RFC 931
|
|
|---|---|---|---|
| Last updated | 2013-03-02 | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 1413 (Proposed Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | (None) | ||
| Send notices to | (None) | ||
Network Working Group M. St. Johns
Request for Comments: 1413 US Department of Defense
Obsoletes: 931 February 1993
Identification Protocol
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.
1. INTRODUCTION
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).
2. OVERVIEW
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.
St. Johns [Page 1]
RFC 1413 Identification Protocol February 1993
3. RESTRICTIONS
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:
<port-on-server> , <port-on-client>
where <port-on-server> is the TCP port (decimal) on the target (where
the "ident" server is running) system, and <port-on-client> is the
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 host B.
For example:
6191, 23
The response is of the form
<port-on-server> , <port-on-client> : <resp-type> : <add-info>
where <port-on-server>,<port-on-client> are the same pair as the
query, <resp-type> is a keyword identifying the type of response, and
<add-info> is context dependent.
The information returned is that associated with the fully specified
TCP connection identified by <server-address>, <client-address>,
<port-on-server>, <port-on-client>, where <server-address> and
<client-address> are the local and foreign IP addresses of the
querying connection -- i.e., the TCP connection to the Identification
Protocol Server. (<port-on-server> and <port-on-client> are taken
from the query.)
For example:
6193, 23 : USERID : UNIX : stjohns
6195, 23 : ERROR : NO-USER
St. Johns [Page 2]
RFC 1413 Identification Protocol February 1993
5. RESPONSE TYPES
A response can be one of two types:
USERID
In this case, <add-info> is a string consisting of an
operating system name (with an optional character set
identifier), followed by ":", followed by an
identification string.
The character set (if present) is separated from the
operating system name by ",". The character set
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