address spoofing

Daniel Senie dts at
Fri Apr 23 23:24:25 UTC 1999

John Leong wrote:
> > Furthermore, whether the RFC [1918] says so or not, I'm going to block
> > these packets at *my* border routers, because:
> Curious as to the cost (added latency) in doing RFC 1918 source address
> filtering on all packets in the context of cost-benfit analysis.

The cost is dependent on the quality of the filtering implementation of
your routers. It's quite possible to implement source address filtering
as a part of ASIC-assisted routing, resulting in wire-speed filtering.
Whether any given vendor has or has not implemented their equipment to
allow wire speed filtering is something you might want to ask salesmen.

As it's something which network providers should be doing, its a
capability that should be demanded of the hardware vendors.

Daniel Senie                                        dts at
Amaranth Networks Inc.  

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