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Conference 7.286::fddi

Title:FDDI - The Next Generation
Moderator:NETCAD::STEFANI
Created:Thu Apr 27 1989
Last Modified:Thu Jun 05 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:2259
Total number of notes:8590

995.0. "CONCENTRATOR DUAL RING FAILOVER QUESTION???" by SALEM::FORGUES () Fri Jun 11 1993 10:39

    
    Hi,
    
    	I have 2 DECconcentrator 500's in a Dual-Ring configuration
        with a couple of dual-homed DECbridge 620's and 2 6000's:
    
                               backbone (ethernet)
    ------------------------------------------------------------------------
       |               |                      |                      |
       |               |                      |                      |
       |               |                      |                      |
       |               |                      |                      |
       |              ________            ________                   |
       |             |        |          |        |                  |
       |             |    B   |          |   B    |                  |
       |             |  620   |          |  620   |                  |
       |              --------            --------                   |
       |                |    \                / |                    |
       |                |     ---------      /  |                    |
       |                |              \    /   |                    |
       |                |     --------- \ --    |                    |
       |                |    /           \      |                    |
       |              ________            \ _______                  |
       |             |        |===========|        |                 |
       |             |    C   |  FDDI     |    C   |--------         |
       |            /|   500  |===========|   500  |        \    -----------    
  -----------      /  --------  DUAL RING  --------          \   |         |
  |         |     /                                           \  | 6000    |
  | 6000    |-----                                             - |         |
  |         |                                                    -----------
  -----------
    
    
    We currently have one 4 port FDDI card in the each concentrator, but 
    we need to add another for two more dual-homed bridges being added
    in the future (3 ports are being used, but we need 2 more ports in 
    each concentrator, thus the need for another card).
     Question:
    
    I want to shutdown each concentrator one at a time to install one
    4 port fddi module , hopefully doing this live without disrupting their 
    application.  Each concentrator does not have an Optical Bypass Relay.
    
     Thank you,
    
    Chuck
    
    
T.RTitleUserPersonal
Name
DateLines
995.1KONING::KONINGPaul Koning, A-13683Fri Jun 11 1993 13:478
That should work fine.  The bridges will switch to the remaining concentrator
very quickly (typically in under a second).  No bypass relays are needed
(or even useful) here since you only have one remaining node on the "ring".
And even if there were other nodes on the ring, that would be true: powering
down a single node on the dual ring simply wraps the ring at that point.  You
don't get problems until you power down two at a time.

	paul