nanog mailing list archives

Re: register.com down sev0?


From: alex () pilosoft com
Date: Thu, 26 Oct 2006 01:31:39 -0400 (EDT)


On Thu, 26 Oct 2006, Patrick W. Gilmore wrote:

There is no single "appropriately[sic] place" which can absorb 50Mpps.  
If you meant "appropriately placed" (as in topologically dispersed
locations), a well crafted attack could still guarantee _at least_ a
partial DoS from an end user PoV.

It is essentially impossible to distinguish end-user requests from
(im)properly created DoS packets (especially until BCP38 is widely
adopted - i.e. probably never).  Since there is no single place - no 13
places - which can withstand a well crafted DoS, you are guaranteed that
some users will not be able to reach any of your listed authorities.
Yeah - I know it hard-to-impossible to do that, and it is a tug-of-war
between worm writers (to generate queries indistinguishable from real
client-resolver-generated queries) and trying-to-detect-malformed-queries
(such as duplicated qid, or from IP space that shouldn't be hitting this
specific node). You probably dealt with more ddos than rest of us
combined, so I bow to your superior knowledge.

I know that the above was just rough back-of-the-envelope, and things
are far more complicated than that, but this discussion does not really
belong to nanog-l.
We disagree.  Keeping large name servers running is _absolutely_ a
network operations topic.  Not only is the defense mostly network based
(since the network is the most likely thing to break), network operators
are the people who get the phone calls when DNS does break.
Sorry - I meant that discussion whether or not register.com is spamming
isn't somewhat offtopic. Of course, DNS operations (and particularly
dealing with "biblical scale" ddos) is very much on-topic. 

-alex





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