Conference netcad::hub_mgnt

    
    
         The fully self contained dual ring is supported today. The
    support has been there ever since the FRS of the DECconcentrator 900MX
    and DECbridge 900MX(now DECswitch 900EF). It requires the MAM to be
    running version 3.0 or later.
    
    

    Thanks Ed, just what I needed to hear !
    
    	Euan
    
    

Hello,

yesterday I tried to create a dual ring on a DEChub900 backplane.
This ring should connect four DECswich900-EF. Two of these were already installed
one year ago, and identifying themselves as DECbridge900-MX.
I was unable to connect both ports (1A/1B) to the backplane, which was possible using
the DECswitches. The only solution was to configure one DECbridge900 as an entrance
into the backplane ring, the other one as an exit of the backplane ring.
When I configured both FDDI ports back, the yellow LED on port A on the bridge in
slot 8 began blinking, and so did the LED on port B on the bridge placed in slot 7.
Using Hubwatch, I saw, that the bridge with the A port yellow saw a neighbour port A,
although there was nothing connected to this port. The connection to the backplane
ring had also not been made yet.
Before doing this, I upgraded the HUB to V4.1.0, and the bridges to V1.5.2.
The only difference I saw, the bridges had HW 0/2, ROM (?) 0/2, while the switches
had HW 1/2. The backplane is HW Rev. F.

Any hints?

Thank you, oetzi

            <<< NETCAD::KALI$USER3:[NOTES$LIBRARY]HUB_MGNT.NOTE;1 >>>
                   -< DEChub/HUBwatch/PROBEwatch CONFERENCE >-
================================================================================
Note 1540.3            self-contained FDDI tings in 900 ?                 3 of 3
UTOPIE::OETTL "hide bug until worst time"            20 lines  20-JAN-1996 08:10
                       -< Problems with backplane ring >-
--------------------------------------------------------------------------------
Hello,

yesterday I tried to create a dual ring on a DEChub900 backplane.
This ring should connect four DECswich900-EF. Two of these were already 
installed one year ago, and identifying themselves as DECbridge900-MX.
I was unable to connect both ports (1A/1B) to the backplane, which was 
possible using the DECswitches. The only solution was to configure one 
DECbridge900 as an entrance into the backplane ring, the other one as an 
exit of the backplane ring.
When I configured both FDDI ports back, the yellow LED on port A on the 
bridge in slot 8 began blinking, and so did the LED on port B on the 
bridge placed in slot 7. 
Using Hubwatch, I saw, that the bridge with the A port yellow saw a 
neighbour port A, although there was nothing connected to this port. 
The connection to the backplane ring had also not been made yet.
Before doing this, I upgraded the HUB to V4.1.0, and the bridges to V1.5.2.
The only difference I saw, the bridges had HW 0/2, ROM (?) 0/2, while the 
switches had HW 1/2. The backplane is HW Rev. F.

Any hints?

Thank you, oetzi

    Perhaps you have run out of backplane channels. What is in each hub
    slot?
    
    How many backplane Ethernet LANS have you defined? Are there any
    concentrators in the ring?
    
    -Mike

The config is:

Slot 8: DEFBA-MA \
Slot 7: DEFBA-MA / DECbridge900-MXes, dual homed, slot 7 is root.
Slot 6: DEFMM-MA
Slot 5: DEFBA-MA (DECswitch900)
Slot 4: DEFMM-MA

Backplane: 1 FDDI Ring, 6 Ethernet LANs.

FDDI -----------+---------------+-------+----------------------------
                |               |       |
Thinwire -------|+--------------|+------|+---------------------------
                ||              ||      ||
Lan1 ---+-------||------+-------||+-----||+--------------------------
        |       ||      |       |||     |||
Lan2 ---|+------||------|+------|||+----|||+-------------------------
        ||      ||      ||      ||||    ||||
Lan3 ---||+-----||+-----||+-----||||----||||-------------------------
        |||     |||     |||     ||||    ||||
Lan4 ---|||+----|||+----|||+----||||----||||-------------------------
        ||||    ||||    ||||    ||||    ||||
Lan5 ---||||+---||||+---||||+---||||----||||-------------------------
        |||||   |||||   |||||   ||||    ||||
Lan6 ---|||||+--|||||+--|||||+--||||----|||||||----------------------
                                            
	DEFMM	DEFBA  	DEFMM	DEFBA 	DEFBA
                      |             |||     |||
   remote1------------+             ||+-----||+------------remote2
                                    |+------|+-------------remote3
                                    +-------+--------------Computer room

Should work fine.

�tzi

	�tzi,
    
    I am confused becuase you said you had four bridges/switches but your
    config only shows three. Also you said you wanted to have a dual ring
    on the backplane but the config picture says dual homed with slot 7
    root.
    
    some generic things to try:
    - reset the problem bridge to current setting and try again;
    - use refresh button on lan interconnect screen of hubwatch
    - reset MAM to current settings
    - reset MAM to factory losing configuration & start over,
    
    
    -Mike
    

Hello,

I was onsite this evening and installed the fourth DECswitch into slot 3.
This switch connects to the same LANs as the switch in slot 5.
re.6
yes, no dual homing.

I resetted the bridges, and was able to connect port 1 as internal ring, but...

I threw awy the FDDI connections and reconnected.
Starting with slot 8, slot 7 and slot 5 worked, the ring was formed.
When I tried to connect port 1 of the switch in slot 3 HUBwatch told me that
the command failed. The FDDI-PMD LEDs didn't start blinking, as they did during
the previous connects.

So this ring is working with one exit and one entry, but not as fully operating
backplane ring.

�tzi

    �tzi,
    
    You have run out of channels on the right side. The solution to your
    problem is move the switch in slot 5 over to one of the left side slots
    (1-4).
    
    Because of the design of the backplane of the DEChub 900, the bottom
    two channels are split between slots 4&5. See figure 1-2 in the "DEChub
    900 Multiswitch Owners Manual" for a picture. 
    
    There are 15 flexible channels (1 full on top connector 10 full on bottom
    connector and 4 split on bottom connector).  You are using the top 6 
    full channels for Ethernet. That leaves 5 full channels plus 4 split
    channels (2 on right half of hub 2 on left half). 
    
    The 3 FDDI devices on the right half of the hub use 6 channels. They 
    use the 2 right-half split channels plus 4 full channels. This leaves
    you with 1 full channel and the 2 left-hand split channels. 
    
    When you add the switch in slot 3, you need to use full channels and
    cannot use split channels since all the other FDDI devices are on the 
    other side of the hub. You need at least 2 full channels but only have
    1. By moving the switch in slot 5 over to the left side of the hub, you 
    are able to use the left-hand split channels and then have enough
    channels. All this channel assignment happens automagically by the hub
    manager.
    
    The reason it works with one exit and one entry, but not with dual-ring
    is because there are fewer channels needed: you don't connect the two
    endpoints together since they connect external to the hub.
    
    When the hubwatch connect fails, look in the "messages" window and
    you'll see that hubwatch is suggesting that you move an FDDI linecard to
    the other side of the hub.
    
    -Mike