mailing list archives
Re: Tightened DNS security question re: DNS amplification attacks.
From: Nate Itkin <nanog () konadogs net>
Date: Tue, 27 Jan 2009 14:59:40 -1000
On Wed, Jan 28, 2009 at 10:36:29AM +1100, Mark Andrews wrote:
< ... snip ... >
deny udp host 188.8.131.52 neq 53 any eq 53
Which pre-supposes that 184.108.40.206 os not emitting queries of
BCP 140 looked at this problem and concluded that sending
REFUSED was the best general guidance that can be given.
While BCP 140 applies to recursive servers, returning REFUSED
to queries which are not within the namespace served by
authoritative servers is entirely consistant with BCP 140.
Agree. Thank you for catching that. I should have elaborated that one
must be very judicious about adding ACLs for the reasons you mentioned.
One of the DOS victims had explicitly said not to expect queries from two
of the recent targets, but yeah, not necessarily a good plan in the general