On Tue, 8 Oct 2002, John M. Brown wrote:
It seems to reason that if people started filtering RFC-1918 on their edge, we would see a noticable amount of traffic go away.
Simulation models I've been running show that an average of 12 to 18 percent of a providers traffic would disappear if they filtered RFC-1918 sourced packets.
That is hard very to believe, unless you are referring to the load on the root nameservers. Since they obviously don't receive a reply, these resolvers will keep coming back.
In addition to the bandwidth savings, there is also a support cost reduction and together, I believe backbone providers can see this on the bottom line of their balance sheets.
We have to start someplace. There is no magic answer for all cases.
RFC-1918 is easy to admin, and easy to deploy, in relative terms compared to uRPF or similar methods.
uRPF is easier: one configuration command per interface. A filter for RFC 1918 space is also one configuration command per interface, and some command to create the filter.
For large and small alike it can be a positive marketing tool, if properly implemented.
Sure. "We can't be bothered to do proper filtering, but since filter 0.39% of what we should, we are cool."