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From: raj@hpindwa.HP.COM (Rick Jones)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: How to limit broadcasts between expensively connected networks?
Message-ID: <36540010@hpindwa.HP.COM>
Date: 11 Jul 90 20:41:59 GMT
References: <3715@altos86.Altos.COM>
Organization: Hewlett-Packard, Cupertino CA
Lines: 31


I have two local area networks connected via a slip connection over X.25.
(I know it's a hack, but I do get reasonable throughput)

		     gateway-A			   gateway-B
      144.1       ---------------   X.25(slip)	----------------  192.68.19
      (ethernet)  | 200.2.10.1  |<<----------->>| 200.2.10.2   |  (ethernet)
    <<---------->>| 144.1.10.98 |		| 192.68.19.42 |<<--------->>
		  ---------------	        ----------------
		  gateway to 200.2.10           gateway to 200.2.10
		  gateway to 192.68.19	        gateway to 144.1

$Begin Response$

	Well, correct me if I am wrong (I'm sure someone will ;-), but
the ONLY *IP* broadcasts that should be going across the gateways
should be directed IP broadcasts. a 144.1.255.255 bcast should not be
forwarded from 144.1 to 192.68.19...

Are your gateways configured to be brouters? That would be the likely
way I can think of where broadcasts - ARPs and other non-IP - might be
passed from gateway to gateway? Rwho, and timed, being IP based,
should not be propagating across the gateways/routers. If they are
indeed brouters, you might try digging deep into the back of the
manuals to find-out how to set-up filtering for the 'bridged' packets
of the brouter.

___   _  ___
|__) /_\  |    Richard Anders Jones   | MPE/XL Networking Engineer
| \_/   \_/    Hewlett-Packard  Co.   | Honest! It is TCP/IP! ;-)
------------------------------------------------------------------------
Being an employee of a Standards Company, all Standard Disclaimers Apply