telnetd(1M)      SYSTEM ADMINISTRATION COMMANDS       telnetd(1M)



NAME
     telnetd - DARPA TELNET protocol server

SYNOPSIS
     in.telnetd

DESCRIPTION
     telnetd is a server which supports the DARPA standard TELNET
     virtual terminal protocol.  telnetd is invoked by the inter-
     net server [see inetd(1M)], normally for requests to connect
     to  the  TELNET  port as indicated by the /etc/services file
     [see services(4)].

     telnetd operates by allocating a pseudo-terminal device  for
     a  client, then creating a login process which has the slave
     side of the pseudo-terminal as its standard  input,  output,
     and  error.   telnetd  manipulates  the  master  side of the
     pseudo-terminal, implementing the TELNET protocol and  pass-
     ing  characters between the remote client and the login pro-
     cess.

     When a TELNET session is started up,  telnetd  sends  TELNET
     options  to  the  client side indicating a willingness to do
     remote echo of characters, to  suppress  go  ahead,  and  to
     receive  terminal  type  information from the remote client.
     If the remote client is willing, the remote terminal type is
     propagated  in the environment of the created login process.
     The pseudo-terminal allocated to the client is configured to
     operate  in  "cooked" mode, and with XTABS, ICRNL, and ONLCR
     enabled [see termio(4)].  telnetd is willing to  do:   echo,
     binary, suppress go ahead, and timing mark.  telnetd is wil-
     ling to have the remote client do:  binary,  terminal  type,
     and suppress go ahead.

SEE ALSO
     telnet(1)

     Postel, Jon, and Joyce Reynolds, ``Telnet Protocol  Specifi-
     cation,''  RFC 854, Network Information Center, SRI Interna-
     tional, Menlo Park, Calif., May 1983.

NOTES
     Some TELNET commands are only partially implemented.

     The TELNET protocol allows for the exchange of the number of
     lines  and  columns  on  the  user's  terminal,  but telnetd
     doesn't make use of them.

     Binary mode has  no  common  interpretation  except  between
     similar operating systems





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telnetd(1M)      SYSTEM ADMINISTRATION COMMANDS       telnetd(1M)



     The terminal type name received from the  remote  client  is
     converted to lower case.

     The packet interface to the pseudo-terminal should  be  used
     for more intelligent flushing of input and output queues.

     telnetd never sends TELNET go ahead commands.

     telnetd can only support 64 pseudo-terminals.














































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