Date: Thu, 22 Feb 1996 22:01:22 -0800 From: David Greenman <davidg@Root.COM> To: graichen@omega.physik.fu-berlin.de (Thomas Graichen) Cc: questions@FreeBSD.ORG Subject: Re: rlogin hangs Message-ID: <199602230601.WAA00593@Root.COM> In-Reply-To: Your message of "22 Feb 1996 18:03:51 GMT." <4gib67$1u7@prospero.physik.fu-berlin.de>
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>sreid@edmbbs.iceonline.com wrote:
>
>: I have a problem, where rlogin works most of the time, but sometimes
>: hangs... I think I saw this in the freebsd-isp mailing list a while ago,
>: but that seemed to be under more stressful conditions...
>
>i'm also nerved by this problem - it's absolutely reproducable (only 2
>machines connected via ethernet) - it's 2.1.0 and everytime i rlogin - exit -
>rlogin it won't work - hangs a minute then again it works - and it's
>_absolutely_ reproducable - if anybody has a solution i may try it out (i
>haven't seen any fix in the commits of the last months)
This sounds like the 2MSL ("TIME_WAIT") wait is somehow coming into play. I
believe that inetd sets the "SO_REUSEADDR" socket option for sockets it
manages, so this must be happening on the rlogin client side instead of the
server...
Can you tell me: Does the problem occur 1) from freebsd to anything,
2) from anything to freebsd, or 3) from freebsd to freebsd ?
The problem sounds like (1) and is probably because some sockets that were
used previously by someone else are now in a "TIME_WAIT" 2MSL state and this
is 60 seconds long. What to do about it, well, that's another thing. The local
port is supposed to be dynamically assigned to the next available port number
since the local port for rlogin isn't important...HOWEVER, rlogin insists on
having the local port be allocated out of the limited number of reserved ports
(it asks for port numbers between 512 and 1023), while telnet has no such
requirement (it asks for ports >=1024). The problem may very well be related
to this and, if so, may also explain why telnet appears to work okay in the
same environment.
-DG
David Greenman
Core-team/Principal Architect, The FreeBSD Project
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