Conference netcad::hub_mgnt

2730.0. "Hub90 management issue...." by SNOFS1::BOYLEBRENDAN (Brendan Boyle) Mon Sep 11 1995 01:53

    Hi!!! Brendan Boyle here from Network Services, Sydney. 
    
    Would you please assist me with a reason for the following DEChub
    behaviour ...
    
    I have a customer with the following situation:
    
    A 16-slot DEChub90 containing a Bridge90FL in slot 8 and slot
    16. These bridges are used in parallel to link to a second 16-slot
    DEChub90 on another level of the building. This provides a failover
    solution via spanning tree in the event of a link/module failure.
    
    This senario is NOT recommended, however, this solution appears to work
    well from a functional standpoint, ie. connectivity fine, and failover
    working as expected (45-60 seconds via spanning-tree). At this point,  
    Hubwatch was implemented. Hubwatch reports an "ERROR" when retrieving  
    information from these hubs. I'm not sure of the exact message,
    however, it appears to resolvable by replacing the Bridge90FL  in slot
    16 of each hub with a DECrepeater90FL. Thus error must be linked to
    having  two bridges in one 16-slot DEChub90.
    
    Could you please explain WHY two bridges are NOT allowed to be
    implemented in a 16-slot DEChub90, ie. is it an operational
    restriction, a management restriction, BUSmaster conflict....
    
    One suggestion is that it is a BUSmaster conflict. If this is the case,
    would the problem be resolved by removing the management cable between
    the HUB90s leaving only the thinwire linking the hubs or even just
    switching off hub-management in the second bridge??
    
    I hope the question is clear...
    
    Thanks
    
    Brendan.