[comp.sys.apollo] telnet hanging

root@merlin.bhpmrl.oz (any of ianh) (04/24/89)

Has anyone noticed telnet hanging while an attempt is being
made to establish a connection ??? For example, when
using telnet from my Macintosh to our 3500 I occasionally get 
the following:

-------------------------------------

# telnet merlin
Trying...
Connected to merlin.
Escape character is '^]'.


Domain/OS sr10 (merlin)

-------------------------------------

it gets this far, and then just sits there (and sits there and sits 
there and ....). What has happened to the login prompt ??? I can do a
kill -1 1 on init to reinitialize things but to no avail.

							ian

ianh@merlin.bhpmrl.oz (Ian Hoyle) (04/24/89)

In article <859@merlin.bhpmrl.oz>, root@merlin.bhpmrl.oz (any of ianh) writes:
> Has anyone noticed telnet hanging while an attempt is being
> made to establish a connection ??? For example, when
.
.
> there and ....). What has happened to the login prompt ??? I can do a
> kill -1 1 on init to reinitialize things but to no avail.
> 

Sorry, but I didn't realise that this message was sent while I wasn't me !!!

					ian

-- 

                Ian Hoyle
     /\/\       Computer Systems Superintendent
    / / /\      BHP Melbourne Research Laboratories
   / / /  \     245 Wellington Rd, Mulgrave, 3170
  / / / /\ \    AUSTRALIA
  \ \/ / / /
   \  / / /     Phone   :  +61-3-560-7066
    \/\/\/      ACSnet  :  ianh@merlin.bhpmrl.oz.au
                Internet:  ianh%merlin.bhpmrl.oz.au@uunet.uu.net

pha@CAEN.ENGIN.UMICH.EDU (Paul H. Anderson) (04/25/89)

	Date: 24 Apr 89 08:08:02 GMT
	From: root%merlin%bruce%murtoa.cs.mu.oz.au%munnari.uucp@uunet.uu.net
	Subject: telnet hanging (SR10.1)
	
	Has anyone noticed telnet hanging while an attempt is being
	made to establish a connection ??? For example, when
	using telnet from my Macintosh to our 3500 I occasionally get 
	the following:
	 
	-------------------------------------
	 
	# telnet merlin
	Trying...
	Connected to merlin.
	Escape character is '^]'.
	 
	 
	Domain/OS sr10 (merlin)
	 
	-------------------------------------
	 
	it gets this far, and then just sits there (and sits there and sits 
	there and ....). What has happened to the login prompt ??? I can do a
	kill -1 1 on init to reinitialize things but to no avail.
	 
	                                                      ian

This is a symptom of a bug in the standard release of the SR10.1 tcp
daemon.  You will notice a telnetd sitting there running continuously,
eating up CPU time, but not doing anything.  Any attempted connections
that happen to try using that /dev/pty? will leave a telnetd spinning
the same exact way.  There are two temporary fixes - first is to remove
the /dev/pty and /dev/ttyp for the corresponding tty, then kill the
processes that were spinning on them.  The other fix is to restart the
tcpd after killing it, recreating all the ptys.

The real fix may be coming in 10.2, but don't hold your breath.  Note
that this problem will cause other related problems, since the connection
actually stays open, even if the user terminates the connection from the
telnet command at their end.  This winds up causing a machine with a
finite number of connection slots to be filled up, thereby denying service
to not only the screwed up Apollo, but also the thing that has a bunch
of open ghost connections.

Paul Anderson
CAEN

	

wescott@LNIC1.HPRC.UH.EDU (Andrew M. Wescott) (05/10/89)

Don't be discouraged, I see this on lots of machines.  Just do a ^]
and start over again.  The world has bigger problems.

Andrew Wescott
University of Hous
ton
Department of Chemical Engineering