[Info-vax] Loosing all LAT connections on one machine in DECNet Network

[Chris Scheers]

JF Mezei wrote:
> Chris Scheers wrote:
> 
>> The DELNI was connected to the company network, which was primarily 
>> 100MB.  Periodically, something on the 100MB network would start 
>> generating enough data to swamp the 10MB DELNI, causing LAT to go down.
> 
> In this case the "DEC" ethernet segment would be fully paralysed, and
> LAT announcements from the PDP-11s would also go away. This chap's
> problem is that only the VAX's LAT service disapears from the decserver.
> 
> 
>> Putting a 10MB switch between the rest of the network and the DELNI 
>> solved the problem.
> 
> If the main ethernet segment has a broadcast storm, then the switch
> would relay all broadcast packets over to the DEC ethernet segment and
> swamp it.

Networks can be funny.  In this case, there was enough traffic to make 
LAT unreliable but not enough to completely swamp the DELNI.  DECnet and 
Pathworks stayed up.

Also in this case, it wasn't a broadcast storm.  It was application 
chatter between two nodes.  (Yes, some of their traffic wasn't switched.)

If you have a broadcast storm you will probably need a bridge to isolate 
the traffic.  (As well as good knowledge about which broadcasts need to 
get where.)

-- 
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Chris Scheers, Applied Synergy, Inc.

Voice: 817-237-3360            Internet: chris at applied-synergy.com
   Fax: 817-237-3074