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Conference netcad::hub_mgnt

Title:DEChub/HUBwatch/PROBEwatch CONFERENCE
Notice:Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7
Moderator:NETCAD::COLELLADT
Created:Wed Nov 13 1991
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:4455
Total number of notes:16761

1440.0. "short packets on a network with 900MX" by CCOF02::PENNO (Murray Penno) Mon Sep 19 1994 01:10

I have a cutomer who has a number of 900MX bridges.  Recently he has started
seeing a large number (5000 per million packets) of short packets (9-10 bytes)
appearing on a segment attached to a 900MX.  The short packets have part of the
destination address and either F's or 5's.

The customer idn't blaming the 900MX yet but I said I would follow it up. Has
anyone seen this behaviour from the 900MX.

Any help or suggestions appreciated.


Murray
T.RTitleUserPersonal
Name
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1440.1Looks like "Remote Failure to Defer"MSDOA::REEDJohn Reed @CBO, DTN:367-6463, KB4FFE, SouthEastMon Sep 19 1994 14:2618
    I have found, that Packets that get their destination address stepped
    on are typically "late collisions", which is the result of a
    mis-configured network.
    
    You might check the distance of all the media in that collision domain, 
    and how many repeaters are between the two furthest points in the
    collision domain (5-4-3 rule). 
    
    In your base note, you comment that the customer has a number of bridges,
    and only recently has he seen this change occur on one port.  Then I
    would check to see what device was last added to that segment.  It may
    be a PC that is having trouble detecting carrier presence, or a cable
    that got caught under a desk, or rolled over by a chair once too many
    times.
    
    Late Collisions are really hard to find.   Good Luck.
    
    JR 
1440.2NETCAD::ANILTue Sep 20 1994 02:227
    Check the Ethernet port screen (new on the currently released
    HUBwatch version).  You get to it by double-clicking on the icon
    of the port on the summary window.  I would look for Ethernet errors
    on the port connected to the problematic LAN, and also the
    port-restarts counter.
    
    Anil