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From: oberman@rogue.llnl.gov
Newsgroups: comp.dcom.sys.cisco
Subject: Re: Dealing with remote routers
Message-ID: <1990Aug17.074457.1@rogue.llnl.gov>
Date: 17 Aug 90 14:44:57 GMT
References: <24867@boulder.Colorado.EDU>
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In article <24867@boulder.Colorado.EDU>, satz@cisco.com (Greg Satz) writes:
> The real question here is why are unreachables having such a deleterious
> effect on your operation? Those messages shouldn't cause any problem on a
> properly functioning TCP/IP implementation. We have "fixed" the problematic
> systems which reacted badly to ICMP unreachables here because we couldn't
> live with that behavior.

Greg, The problem is that under 4.3BSD (Tahoe), when an ICMP host/net
unavailable message is received, all sessions to the effected node are
terminated. And Tahoe implementations are VERY common around here. While I
don't know if it's our cisco, we have been having problems with this here.
Attempts by remote sites to get large files from Tahoe systems often fail with
reachability errors.

I'm told the Reno release "fixes" this by not making an unreachable a fatal
condition unless it persists. I hope to have my software patched to work this
way in a couple of week or so. But, in the meantime, it's a real pain.

					R. Kevin Oberman
					Lawrence Livermore National Laboratory
					Internet: oberman@icdc.llnl.gov
   					(415) 422-6955