Conference netcad::hub_mgnt

2568.0. "Starnge Hubmanager Behaviour ?" by GIDDAY::STANISLAUS () Thu Jul 27 1995 05:30

	Problem Statements:
	-------------------

	First problem:
	--------------
Config.

	All DEchub 900 units with ver 3.1 S/W in the Hubmanager and Hubwatch
version 3.1 and IP services modules are all DR900TMs in all Hubs with ver 1.1.0
Firmware. 

	A network with 10 Hubs works fine. A 11th Hub is added. Hubwatch is
unable to see 2 or 3  of the 11 Hubs. You can't even ping from the Hubwatch PC
to those 2 or 3 Hubs, that were working fine before the 11th Hub was added.

	To get over the problem customer has to do one of the following:

	1)Reset Management Module of the Hubs that he can't Ping to, to  the 
current settings. Then Ping and Hubwatch works fine to that Hub.

				`OR

	2)Remove and re-insert the DR900TM (IP services module) of the
not-responding Hub and that makes that Hub again communicate with the Hubmanager
PC. 


	The above problem happened on this site when he added the 11th, the 12th
and the 13th Hub.


	Second Problem:
	---------------

	Resetting the management module to current settings as far as I know
should not drop user data through the hub modules - terminal servers, repeaters,
etc. This is not true. When we reset the management module to current settings
terminal server connected LAT users in that Hub lost connection to LAT hosts.
Is this normal behaviour ?


Note:
-----

	All the above Hubs have simple configurations. No Flexi-Channel being
used. Just the Blue-Thinwire Backplane connections.


Alphonse

Hi Alphonse -

>	A network with 10 Hubs works fine. A 11th Hub is added. Hubwatch is
>unable to see 2 or 3  of the 11 Hubs. You can't even ping from the Hubwatch PC
>to those 2 or 3 Hubs, that were working fine before the 11th Hub was added.
>

Let me comment on your first problem.  It's not one
that I've heard of before.  All hubs are strictly
independent of one another - adding a hub to a network
will not cause any reconfiguration of IPS in another
hub.  If the new hub or one of its modules has the
same IP address as a hub's IPS address, that would
disrupt communications to those two hubs, but not
to others.

What could cause your scenario is a temporary
repeater loop.  It could cause a blast of frames
to the DETMM providing IPS that would knock it
out of the "Up" state to "Unknown".  If it oscillates
quickly several times between these two states,
the MAM can deconfigure IPS.

The two actions you described are the classic fixes
for IPS gone deconfigured.

>	To get over the problem customer has to do one of the following:
>
>	1)Reset Management Module of the Hubs that he can't Ping to, to  the 
>current settings. Then Ping and Hubwatch works fine to that Hub.
>
>				`OR
>
>	2)Remove and re-insert the DR900TM (IP services module) of the
>not-responding Hub and that makes that Hub again communicate with the Hubmanager
>PC. 

Maybe a terminal servers person can answer your second
question.

    - Dotsie