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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

647.0. "DB90s and legal configuration question" by GIDDAY::COOPER () Mon Jan 24 1994 04:01

HI,

I have had a query regarding the following configuration. The customer 
already has DB90s connected on the workgroup side of another DB90 and
it works fine at this point. He now wishes to add more DB90s to the 
workgroup side and wants to know if it is a supported configuration.
The number of nodes total on the workgroup side of the bridge in question
is only about 37 so the 200 node limit is not a problem.

The DB90 manual states that having a DB90 on the workgroup side is not
supported but it doesnt state the reasons. Are there any Spanning Tree
problems in doing this.?


Any help much appreciated.

Thanks in advance,
Steve Cooper
Sydney CSC

--------------------------------------------------------------------------

Network Diagram

Note: W = workgroup side
      B = backbone side

              | W                             | W        
           +-------+                      +-------+
           | DB90  |                      |  DB90 |
           +-------+                      +-------+
              | B                             | B
              |                               |
            +---+                           +---+
            |FOT|                           |FOT|
            +---+                           +---+
              |                               |
              +------------+   +--------------+
                           |   |
                       +-----------+
                       | Fibre Hub |
                       +-----------+
                             |
                           +---+
                           |FOT|
                           +---+
                             |
                          +-----+
                          |DEMPR|
                          +-----+
                           ||||
                +----------+||+-------------------------+
                |           |+-----------+              |
                | B         |            | B            | B
           +---------+      |        +---------+   +---------+
           |Proposed |      |        |Proposed |   |Proposed |
           | DB90    |      |        | DB90    |   | DB90    |
           +---------+      |        +---------+   +---------+
                | W         |             | W           | W
             LAVC (5 nodes) |         LAVC (5 nodes) LAVC (5 nodes)
                            | W
                         +-----+
                         | DB90|
                         +-----+
                            | B
                         +-----+
                         |DEMPR|
                         +-----+
                          |||||
                     rest of network incuding translans to other sites
                     N.B. a translan is the root bridge
T.RTitleUserPersonal
Name
DateLines
647.1QUIVER::SLAWRENCEMon Jan 24 1994 14:0910
    That configuration looks like it will work.
    
    Be very carefull that the configuration remains a tree with no
    redundant connections (no two DECbridge90 workgroup ports can reach one
    another).
    
    The problem with configurations like this one is that it becomes
    increasingly difficult to keep track of the number of systems on the
    workgroup side of the 'highest' DB90; keep an eye on the number of
    addresses in its workgroup.