[c-nsp] DNS amplification

Sun Mar 17 15:33:01 UTC 2013

	Yes, BCP38 is the solution.

	Now, how widely is deployed?

	Someone said in the IEPG session during the IETF86 that 80% of the
service providers had done it?

	This raises two questions for me. One, is it really 80%, how to measure it?

	Second, if it were 80%, how come the 20% makes so much trouble and how
to encourage it to deploy BCP38?

	(well, actually 4 questions :)

Regards,
as

On 3/16/13 7:24 PM, Jon Lewis wrote:
> On Sat, 16 Mar 2013, Robert Joosten wrote:
> 
>> Hi,
>>
>>>> Can anyone provide insight into how to defeat DNS amplification
>>>> attacks?
>>> Restrict resolvers to your customer networks.
>>
>> And deploy RPF
> 
> uRPF / BCP38 is really the only solution.  Even if we did close all the
> open recursion DNS servers (which is a good idea), the attackers would
> just shift to another protocol/service that provides amplification of
> traffic and can be aimed via spoofed source address packets.  Going
> after DNS is playing whack-a-mole.  DNS is the hip one right now.  It's
> not the only one available.