Network Operators and smurf

John A. Tamplin jat at
Fri Apr 24 23:06:50 UTC 1998

On Fri, 24 Apr 1998, Karl Denninger wrote:

> Well, there is a simple knob for this:
> If the Knob is turned "ON", then any packet from a source address which is 
> not routed to the interface it came in on is dropped.
> This works for static, dynamic, and all other kinds of routing.    It will
> solve the problem and is trivial to implement - if any of the vendors care.

It doesn't work for asymmetric routing as you describe it above. If you
modify your criteria to be that there are no valid routes out that
interface, you would only break transient routing conditions, but
depending on how the router stores routes it may not be possible (or
desirable due to memory requirements) to implement. 

John Tamplin					Traveller Information Services
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