[14342] in North American Network Operators' Group
Re: Broadcast pings.
daemon@ATHENA.MIT.EDU (Paul Ferguson)
Tue Dec 23 19:06:06 1997
Date: Tue, 23 Dec 1997 18:59:36 -0500
To: Phil Howard <phil@charon.milepost.com>
From: Paul Ferguson <ferguson@cisco.com>
Cc: nanog@merit.edu
In-Reply-To: <199712232332.RAA00628@charon.milepost.com>
At 05:32 PM 12/23/97 -0600, Phil Howard wrote:
>
>When a packet arrives, take note of the interface and gateway it came from.
>Check the route tables for where a reply to this packet could be delivered.
>Don't choose only the best route, but compare where the packet came from
>with all valid reply routes (except broad defaults larger than a certain
>size that can be configured). If the packet came from where it is valid
>to reply, then allow the packet to proceed. If not, then discard it (an
>ICMP probably won't make it back to the right place anyway).
>
Yes. Some of us call this 'unicast RPF'.
Your point is well taken. ;-)
- paul
