ferguson at cisco.com
Tue Dec 23 23:59:36 UTC 1997
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. ;-)
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