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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

613.0. "Bridge/configuration problem" by ODIXIE::RICHARDSON (Are we there yet??) Thu Jan 13 1994 09:17

    I'm having a problem with errors showing up on a DECbridge 90 using
    HUBwatch for Windows.
    
    Initially, the hub I was trying to manage had V1.5 of firmware which I
    assumed was the problem (the agent has V1.1).  Instead of upgrading a
    bridge that was in operation on the network, we obtained another
    "spare" bridge and hub which we hooked on to the end of the thinwire
    backbone segment.  Now, I always thought the backbone segment was
    supposed to go into the front of the bridge in the thinwire port (no
    "t" connector) and have the Hub's thinwire port on the side terminated
    (there were no hubs daisychained).  However, when we added the hub in
    this fashion we immediately got "circuit-up, circuit-down" failures on
    the servers and the network went down which was not good news.
    
    When we pulled the backbone thinwire out of the front and plugged it
    into the side of the hub, the network came back up.  However, the 200
    node limit light (#6) on the front of the bridge lit up like a
    Christmas tree which wasn't surprising.  I loaded the firmware from one
    of the servers just fine in this configuration.
    
    However, from HUBwatch, we still kept getting errors everytime the
    bridge was polled - "workgroup port down" and "backbone port down".
    
    Am I doing something wrong?  I must be.  I know that thinwire
    connection is NOT supposed to go into the side of the hub but rather
    the front of the bridge.  Does anyone know why this WOULDN'T work and
    the screwy way we have configured is working (at least as far as the
    network staying up).
    
    Thanks
    
    Cindy
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613.1wrong connectionQUIVER::SLAWRENCEThu Jan 13 1994 09:319
    Both thinwire ports on the DECbridge 90 are endstation ports; they DO
    need a T connector.
    
    The port on the flat upper surface (in the 'lanhole') is the Workgroup
    port, and may be used ONLY when the bridge is Standalone; in the hub,
    the Workgroup port is the backplane thinwire.
    
    The front bezel thinwire is the backbone port - it does require a T
    connector.
613.2thinwire is in HUB thinwire port..ODIXIE::RICHARDSONAre we there yet??Thu Jan 13 1994 10:129
    That's what I thought.  The front bezel T port should be connected to
    the backbone.  I tried this and it brings the network down.  The switch
    on the front is selected for the thinwire.  The only thing that works
    is connecting the backbone thinwire to the side of the DEChub -which is
    wrong, (but it works!!)...
    
    What would cause this?
    
    
613.3More info.CGOS01::DMARLOWEdsk dsk dsk (tsk tsk tsk)Thu Jan 13 1994 11:243
    Could you include a diagram of what you have and we'll try to fix.
    
    dave
613.4here's moreODIXIE::RICHARDSONAre we there yet??Thu Jan 13 1994 12:0546
    
    Here goes - I'm not a good "artist"
    
    Original config:
    
    ...------------------------------------| (terminator)
      thinwire "backbone"    |      |
                         server   server
                                               ________________________
                                              |      ...|   | A |brg|P|
    Then I added:                             |      ...|   | G | 90|O|
                                              |      ...|   | E |   |W|
    ...-----------------------------------------------------------  |E|
      thinwire "backbone"    |      |         |         |   | N |   |R|
                         server   server      |         |   | T |   | |
                                              |________________________
                                         ^
    					Thinwire backbone segment ^
    					(no t-connect into bridge)
    The thinwire "switch" is set.
    
    This causes the network to go down (line synchronization lost)
    
    The hub thinwire connection (on side) is NOT terminated.  ??
    
    If I connect the thinwire backbone segment to the hub
    
                                               ________________________
                                              |      ...|   | A |brg|P|--|
                                              |      ...|   | G | 90|O|  |
                                              |      ...|   | E |   |W|  |
    ...------------------------------------------------------------------|  
      thinwire "backbone"    |      |         |         |   | N |   |R|
                         server   server      |         |   | T |   | |
                                              |________________________
    
    
    the network doesn't go down, but the 200 node workgroup limit exceeded
    light goes on (which is what I would expect since I now have a bridge
    90 which thinks it's workgroup is the backbone segment.  However, this
    did enable me to load the V3.1 firmware.
    
    Is that enough info?  If not, let me know.
    
    Thanks
    
613.5SLINK::HOODI'd rather be surfingThu Jan 13 1994 12:193
You need a terminator on the front-panel thinwire connection from the
backbone network to the bridge.

613.6this should do it...QUIVER::SLAWRENCEThu Jan 13 1994 13:5124
       >                                            ________________________
       >                                           |      ...|   | A |brg|P|
       > Then I added:                             |      ...|   | G | 90|O|
       >                                           |      ...|   | E |   |W|
       > ...-----------------------------------------------------------  |E|
       >   thinwire "backbone"    |      |         |         |   | N |   |R|
       >                      server   server      |         |   | T |   | |
       >                                           |________________________
       >                                      ^
       >                                (no t-connect into bridge)
       > The thinwire "switch" is set.
       >
       > This causes the network to go down (line synchronization lost)
       >
       > The hub thinwire connection (on side) is NOT terminated.  ??
    
    Your config is fine with just 2 changes:
    
    	Connect the thinwire "backbone" segment to the bridge front bezel
             connector WITH a T connector.
    
        Terminate the backplane 'thinwire' with a terminator on the right 
             side of the hub.