Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!ucbvax!AHWAHNEE.STANFORD.EDU!dcrocker
From: dcrocker@AHWAHNEE.STANFORD.EDU (Dave Crocker)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: SO_KEEPALIVE considered harmful?
Message-ID: <8905250638.AA21706@ucbvax.Berkeley.EDU>
Date: 23 May 89 21:03:13 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 16

I tried to avoid saying that keepalives should be prohibited, except,
perhaps, from an aesthetic point of view.  Since aesthetics often are
altered by reality, it is no great concession to acknowledge the 
occasional need for the mechanism.

My point was that they are dangerous and therefore should be used VERY
judiciously.  Craig's note puts this point forward in more detail.

It is worth adding that the excessive use of keepalives has removed a
feature that used to be in TCP and has been recently re-documented by
Bob Braden:  TCP used to be remarkably robust against temporary
outages.  If you were willing to wait, so was TCP.  Now, an outage of
a very short time -- on some implementations, as short as 1-2 minutes --
will abort the connection.

Dave