DNS Amplification attack?

jay at miscreant.org jay at miscreant.org
Wed Jan 21 03:25:49 UTC 2009

Quoting Chris Adams <cmadams at hiwaay.net>:

> Once upon a time, jay at miscreant.org <jay at miscreant.org> said:
>> I've also noticed that on a server running BIND 9.3.4-P1 with
>> recursion disabled, they're still appear to be getting the list of
>> root NS's from cache, which is a 272-byte response to a 61-byte
>> request, which by my definition is an amplification.
> Add "additional-from-cache no;" to the options{} section of your
> named.conf.
> --
> Chris Adams <cmadams at hiwaay.net>
> Systems and Network Administrator - HiWAAY Internet Services
> I don't speak for anybody but myself - that's enough trouble.

Thanks for the response Chris.

I'm running higher versions of BIND, so don't see this behaviour. But  
I will pass it on to the ISP in question ;)

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