23 Dec
1997
23 Dec
'97
6:59 p.m.
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