home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Columbia Kermit
/
kermit.zip
/
newsgroups
/
misc.19980901-19981211
/
000091_news@newsmaster….columbia.edu _Thu Oct 1 10:33:57 1998.msg
< prev
next >
Wrap
Internet Message Format
|
2020-01-01
|
3KB
Return-Path: <news@newsmaster.cc.columbia.edu>
Received: from newsmaster.cc.columbia.edu (newsmaster.cc.columbia.edu [128.59.35.30])
by watsun.cc.columbia.edu (8.8.5/8.8.5) with ESMTP id KAA01187
for <kermit.misc@watsun.cc.columbia.edu>; Thu, 1 Oct 1998 10:33:54 -0400 (EDT)
Received: (from news@localhost)
by newsmaster.cc.columbia.edu (8.8.5/8.8.5) id KAA05848
for kermit.misc@watsun; Thu, 1 Oct 1998 10:33:53 -0400 (EDT)
Path: news.columbia.edu!news.new-york.net!mobster.newyork.wirehub.net!newsfeed.wirehub.nl!ayres.ftech.net!news.ftech.net!newsfeed.nacamar.de!nntp.news.xara.net!xara.net!server5.netnews.ja.net!server3.netnews.ja.net!server4.netnews.ja.net!server2.netnews.ja.net!bham!not-for-mail
From: Brian McCauley <B.A.McCauley@bham.ac.uk>
Newsgroups: comp.protocols.kermit.misc
Subject: Re: Telnet disconnect
Date: 01 Oct 1998 13:09:19 +0100
Organization: Wolfson Computer Lab, University of Birmingham, England
Lines: 34
Message-ID: <u9hfxoqya8.fsf@wcl-l.bham.ac.uk>
References: <F04wA5.DqL@cix.compulink.co.uk>
NNTP-Posting-Host: wcl-l.bham.ac.uk
X-Newsreader: Gnus v5.3/Emacs 19.34
Xref: news.columbia.edu comp.protocols.kermit.misc:9274
lsystemsd@cix.compulink.co.uk ("Lygo Systems") writes:
> I have a number of users connecting with MS-DOS Kermit telnet sessions
> into Redhat Linux (4.2 & 5.1). If they close the connection with the
> normal Kermit exit command without first logging off, then the telnet
> session is closed on Linux which is just what I want. If, however, they
> reboot their PC with ALT CTL DEL then the session stays active.
>
> The reason that this is a problem is that they are running the Pick/D3
> database which has a limited number of active users allowed to be logged
> on at the same time. If they reboot their PC then that will effectively
> lose one user unless the previous session is automatically logged off.
> Pick has a couple of commands that in theory should deal with the
> situation: DCD-ON and TRAP DCD EXIT. In other words if DCD is lost then
> the session should be automatically closed. But it ain't happening...
The TCP connection is implemented over the connectionless IP layer -
there is no "carrier". The only way that TCP gets to find out that
the PC has been rebooted is if it sends an IP packet. It only does
this if there's something to send.
There is such a thing as a TCP keepalive option. This will cause TCP
connections to timeout eventually but not soon.
I guess you could hack the telnetd to send a telnet NOP
periodically as a sort of application level keepalive.
--
\\ ( ) No male bovine | Email: B.A.McCauley@bham.ac.uk
. _\\__[oo faeces from | Phones: +44 121 471 3789 (home)
.__/ \\ /\@ /~) /~[ /\/[ | +44 121 627 2173 (voice) 2175 (fax)
. l___\\ /~~) /~~[ / [ | PGP-fp: D7 03 2A 4B D8 3A 05 37...
# ll l\\ ~~~~ ~ ~ ~ ~ | http://www.wcl.bham.ac.uk/~bam/
###LL LL\\ (Brian McCauley) |