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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

3049.0. "A/B on Front and M on the backplane" by SCASS1::DAVIES (Mark, SCA Area Network Consultant) Fri Dec 08 1995 15:05

    My customer has 2 DECswitch 900EFs and 2 DECconcentrator 900 and some
    PEswitches in his DEChub 900.
    
    He has 3 FDDI rings in the backplane, as follows:
    
    FDDI 1:	DECswitch 900 EF + PEswitch 900MX
    
    FDDI 2:	DECswitch 900 EF + PEswitch 900MX
    
    FDDI 3:	2 DECconcentrator 900MX 
    
    He wants to have each of the above modules pairs have a DAS connection
    back to the GIGAswitch/FDDI.
    
    On the DS900EF and DC900MX, is it possible to have the A/B ports active
    on the front and also an "M" port on the back to connect the other
    module of the pair.
    
    If not, then I guess he will have to have a SAS connection for the
    DS900EF/PE900TX pairs.
    
    When I look at the HUBwatch options for this, I see one called " Root
    of a dual homed tree" that has A/B on the front and M on the backplane
    active.
    
    Is this right? 
    
    He doesn't want dual homed, he wants DAS.
    
    Thanks,
    
    Mark
    
T.RTitleUserPersonal
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3049.1exitNETCAD::B_CRONINFri Dec 08 1995 18:3616
    
    The concentrator ring could do the M port on the back, but if he wants
    a DAS ring from the G/S, there is no need. Just aim an A port out the
    front of the 1st con, and a  B port out the front of the second, and 
    connect them to the gigaswitch as one dual ring. 
    
    
    The bridges only have 2 PHYs, so they can never do anything needing 
    3 PHYS (such as AB front, M back). In that case, you are right, they 
    can only make a SAS connect back to the G/S. For the sake of
    simplicity, put an S port out the front of the EF, an M port into the 
    backplane. Then make the PE ports M and S into the backplane, and 
    hook them up. Then hook the S port of the EF to the G/S. 
    
    If you need more info, note 2340 explains this in gory detail