Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!ucsd!sdd.hp.com!zaphod.mps.ohio-state.edu!mips!intrepid!len From: len@mips.COM (Len Lattanzi) Newsgroups: comp.unix.ultrix Subject: Re: TCP chokes between Ultrix 4 and 3.1c systems Message-ID: <41981@mips.mips.COM> Date: 9 Oct 90 07:22:51 GMT References: <1990Oct9.031736.2569@hayes.fai.alaska.edu> <1990Oct9.040440.23066@watcgl.waterloo.edu> Sender: news@mips.COM Reply-To: len@mips.COM (Len Lattanzi) Organization: MIPS Computer Systems, Inc. Lines: 27 In article <1990Oct9.040440.23066@watcgl.waterloo.edu> idallen@watcgl.waterloo.edu (Ian! D. Allen [CGL]) writes: :>Yet another amusing feature. I think this may have come up quite some time :>back. When I use ftp, telnet, or even mail to a DS3100 running Ultrix 3.1c :>from my DS5000 running Ultrix 4.0, the connection hangs whenever 512 or more :>bytes are sent from a single operation (e.g., mail messages, ftp files, :>or commands in telnet). The same thing happens when the folks on the other :>end try to talk to me. Neither of us have any problems talking to non-Ultrix :>systems, and I can talk to other Ultrix 4.0 systems just fine. : :Aha! We see this behaviour between real MIPS machines and our Ultrix :3.1C DECsystem 5400's. BSD Vaxen, Suns, other machines, have no :problem talking to the 5400's, but connecitons from those three MIPS :machines hang on large packets. And it's asymmetric -- we can rcp *out* :of the DS5400, but not in. :-- :-IAN! (Ian! D. Allen) idallen@watcgl.uwaterloo.ca idallen@watcgl.waterloo.edu : [129.97.128.64] Computer Graphics Lab/University of Waterloo/Ontario/Canada The first M/120's did not support trailers on enet packets and silently hung connections to other hosts that sent them. (just a guess but try turning off trailers on all interfaces -- I have no idea if Ultrix 3.1/4.0 enet hangs have similar causes) -- \ Len Lattanzi ({ames,pyramid,decwrl}!mips!len) I would have put a disclaimer here but I already posted the article.