Conference netcad::hub_mgnt

3350.0. "IP Servcies Module NOT ACTIVE when using more than one" by KERNEL::CHOPRAA () Mon Mar 11 1996 14:55

Hi,

A customer has a problem with multiple IP addresses/IP Services modules on a
DEChub 900.  He can configure two seperate modules as IP Services Modules each
with different IP Addresses.  The modules in question are a DECrepeater 900TM
(slot 5) and a DECconcentrator 900MX (slot 8).

Firmware revisions are

	DECconcentrator 900MX	3.1.1
	Backplane 		4.1.1

When he views the IP configuration using option 3 "Show Current Settings" from
the HUB900 console, he gets the following as you would expect

Interface	IP Address	Subnet Mask	Def. Gateway	Other Info
---------	----------	-----------	------------	----------
OBM Port	xx.xxx.x.01	255.255.255.0			Speed 9600 bps
Hub Slot 8 	xx.xxx.x.02	255.255.255.0			Active
Hub Slot 5 	xx.xxx.x.03	255.255.255.0			Active
==============================================================================

With Hubwatch, he can manage the hub using both IP addresses and all works
fine.  BUT.

On a couple of occasions, he has tried to manage the hub using the IP address
associated with the Concentrator (Slot 8) and has failed with a timeout.  Using
the alternative IP address assoaciated with the Repeater (Slot 5) works fine.

When looking at the IP configuration from the hub console screen he sees the
following.  (NOTE:  Not active under the Other Info column).

Interface       IP Address      Subnet Mask     Def. Gateway    Other Info
---------       ----------      -----------     ------------    ----------
OBM Port        xx.xxx.x.01     255.255.255.0                   Speed 9600 bps
Hub Slot 8      xx.xxx.x.02     255.255.255.0                   Not Active
Hub Slot 5      xx.xxx.x.03     255.255.255.0                   Active
==============================================================================

All other network comms seem to be o.k.

Questions.

Is this a feature (bug!)?
If so, is there a fix?
What does "Not Active" in the "Other Info" column mean?
If the concentrator is up and running, why should the IP services functionality
be "not active"?


Thanks

Anil Chopra                             Tel:  01256-373746 (Direct line)
UK Comms Support                        DTN:  7833-3746
Digital Customer Support Centre         Fax:  01256-841494
Multivendor Customer Services           Internet:  [email protected]

Hi Anil -

"Not Active" in the "Other Info" column means the concentrator
won't be serving IP traffic for you.  This is a bug.  Here is
a possible scenario: At some point the concentrator bounced down
and then back up.  Before it went down, the hub sent it some IP 
services traffic.  The message timed out, and was stuck in a
retry queue.  The retry was tried while the concentrator was coming
back up, but not fully up (bug one).  The hub's own lower protocol
layers returned an error because the module was not ready.  The hub 
marked it Not Active or Not Configured.  Once in that state, the
hub leaves it there, never trying again (bug two) until the hub is 
reset.

A fix for this problem will appear in a future hub version.
Meanwhile, use your most stable modules for in-band IP services.

	Dotsie

Dotsie,

Thanks for the answers and explanation.  I'll pass that on to my customer 
(replacing the word BUG with FEATURE!).

You also mentioned "most stable modules".  Do we know which modules are more
stable than others?

Anil

"Most stable" in your environment - empirical findings are the
best guide.  All our modules work fine when sitting around in
a quiet hub. :-)  However, in test situations, older repeater 
versions can run out of buffers, and blasting any IP server 
with long periods of high-bandwidth traffic (as in Digital 
UNIX /ping -flood -loop) can cause mischief.  

What you already have set up, with two in-band IP servers for 
the hub, it a good strategy.

	Dotsie

Thanks for the help

Anil