Things to do to make the network better

Owen DeLong owen at DeLong.SJ.CA.US
Mon Jan 5 15:56:54 UTC 1998


> I will also point out that many of the recent "smurf" attacks and
> similar problems people are having on the net would be gone if people
> would just carefully filter internal/external addresses on their
> border machines, that is, prevent packets claiming to be from "inside"
> networks from coming in from the "outside", and prevent packets
> claiming to be from "outside" networks from going out from the
> "inside". The latter will stop your network from *ever* being the
> source of a wide variety of packet forgery attacks, and is necessary
> to being a good network citizen. The former will stop your network
> from being the subject of a wide variety fo packet forgery attacks,
> and is necessary to make your customers even remotely safe on the net.

That's great if you're a downstream provider with no transit customers.
However, when you become a transit provider, it becomes much more difficult
to determine inside vs. outside, since you're more in the middle between
two "outsides" that pass traffic through you.

Owen



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