FYI: I am being threatened for posting operationally relevant criticism of
mis-operation of the F DNS Root server on the DNSOP list.
--
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---------- Forwarded message ----------
Date: Fri, 23 Sep 2005 15:55:20 -0700
From: David Kessens <david(_dot_)kessens(_at_)nokia(_dot_)com>
To: Dean Anderson <dean(_at_)av8(_dot_)com>
Cc: David Meyer <dmm(_at_)1-4-5(_dot_)net>, Rob Austein
<sra(_at_)hactrn(_dot_)net>,
Bert Wijnen <bwijnen(_at_)lucent(_dot_)com>
Subject: [david(_dot_)kessens(_at_)nokia(_dot_)com: Re: [dnsop] An attack that
DNSSEC would
have defended against...]
Dean,
To avoid any misunderstandings: My message is an official warning to
you that I will propose to the IESG to remove your posting privileges
if I see one more abusive mail from you.
Thanks,
David Kessens
---
----- Forwarded message from David Kessens
<david(_dot_)kessens(_at_)nokia(_dot_)com> -----
Date: Fri, 23 Sep 2005 15:36:11 -0700
From: David Kessens <david(_dot_)kessens(_at_)nokia(_dot_)com>
To: Dean Anderson <dean(_at_)av8(_dot_)com>
Cc: Harald Tveit Alvestrand <harald(_at_)Alvestrand(_dot_)no>,
dnsop(_at_)lists(_dot_)uoregon(_dot_)edu
Subject: Re: [dnsop] An attack that DNSSEC would have defended against...
Dean,
You are welcome to post to this list if you have DNS operational
issues to discuss.
Any issues that you might have with ISC are outside the charter of
this working group and I would like to request you to take them up
privately with ISC.
Thanks,
David Kessens
---
On Fri, Sep 23, 2005 at 06:09:23PM -0400, Dean Anderson wrote:
Harald, you may be right about DNSSEC protecting from this. I haven't looked
at
your data, yet. However, you probably aren't about to be very well protected
by
DNSSEC, despite the progress of specifications on DNSEXT.
DNSSEC isn't deployable on F-root nor the other anycast'ed* roots, nor a lot
of
other anycast'ed non-root servers. DNS servers with the Anycast Extension are
increasingly popular due to suppression of discussion of negative aspects of
the
Anycast Extension on forums such as Nanog as recently as May, 2005 because
only
information that promotes ISC's view is allowed on Nanog, misleading network
operators about the Anycast Extension. Many root server operators accepted
ISC's assurances as an unofficial IETF liason and deployed Anycast Extension
on
production servers and on root servers in violation of RFC 2870**. They appear
not to have understood that they were deploying an untested, undocumented, and
unapproved Anycast Extension.
And despite substantiated criticism on DNSEXT and DNSOP by persons including
Dan
Bernstein, Iljitsch van Beijnum, Dean Anderson, and others since the 2002
Nanog
presentation by ISC, ISC has not yet even publicly acknowledged the problems
with the Anycast Extension, and continues to promote the extension as
completely
safe. ISC even describes it to prospective customers as "uncontroversial",
despite the controversies on DNSEXT, DNSOP, and Nanog beginning after the
Nanog
presentation in 2002.
The Anycast Extension is now proposed to the GROW working group some 3 years
after being described to Nanog as operationally safe and stable. At present,
the Anycast Extension proposal appears to be dead or dying on both DNSOP and
GROW WGs because of evidence that it can't work in general, and the
specialized
conditions where it can work are uninteresting to the current users such as
root
DNS operators and other DNS operators, and thus uninteresting to ISC.
The only reason there are no present complaints with root operations is that
DNS
is mostly still stateless small UDP packets, reducing to RFC 1546 Anycast***,
which works fine with stateless small UDP packets. And it may well be that
those
working on DNSSEC testing comply with the assumptions stated on the Anycast
Extension.
So the question is when will F-root and other roots be able to handle TCP and
large UDP packets from any internet host, including those hosts serviced by
networks that use fine-grained load-splitting as described by RFC1812?. When
will operators be informed of these problems by ISC?
Critics of these problems, particularly Dan Bernstein and Dean Anderson, have
been attacked personally by persons generally associated with ISC or friendly
to
ISC with no remedial action by the respective organizations (IETF and Nanog)
in
spite of well-documented complaints. Uncontrolled personal corruption at the
IETF and Nanog appears to be preventing actual progress.
--Dean
[* the Anycast Extension
http://www.ietf.org/internet-drafts/draft-ietf-grow-anycast-01.txt doesn't
work
in general because routers are allowed by RFC1812 to do fine-grained "load
splitting" if they wish. Fine-grained load splitting, also known as Per Packet
Load Balancing (PPLB) and other names, prevents Anycast from being used with
TCP
or large UDP packets and fragments. The draft documents a number of
assumptions
that have to be true in order for the Anycast Extension to work. These
assumptions aren't true in general.]
[** RFC 2870 section 2.6 specifies that Root DNS server operators must operate
servers that respond to _any_ Internet host. That is, Root nameservers that
only work for say, 95% of the world are not acceptable.
2.6 Root servers MUST answer queries from any internet host, i.e. may
not block root name resolution from any valid IP address, except
in the case of queries causing operational problems, in which
case the blocking SHOULD last only as long as the problem, and be
as specific as reasonably possible.
]
[*** RFC1546 notes that:
It is important to remember that anycasting is a stateless service.
An internetwork has no obligation to deliver two successive packets
sent to the same anycast address to the same host.
]
On Fri, 23 Sep 2005, Harald Tveit Alvestrand wrote:
I'm not sure this is on-topic for this list, but may be an illustrative
story....
I had some percentage of the queries for a domain I use hijacked by an
attacker last week. The technique involved was interesting to me.
Moral: Know your secondaries, and what happens to them..... if someone
steals your secondary's NAME, you're toast.
If I'd had DNSSEC, and the people looking it up had had DNSSEC, this would
have been a detectable DOS attack, not a stealth redirection attack.
Detailed writeup: http://www.alvestrand.no/subjects/dns-attack-1.html
Harald
.
dnsop resources:_____________________________________________________
web user interface: http://darkwing.uoregon.edu/~llynch/dnsop.html
mhonarc archive: http://darkwing.uoregon.edu/~llynch/dnsop/index.html
--
Av8 Internet Prepared to pay a premium for better service?
www.av8.net faster, more reliable, better service
617 344 9000
.
dnsop resources:_____________________________________________________
web user interface: http://darkwing.uoregon.edu/~llynch/dnsop.html
mhonarc archive: http://darkwing.uoregon.edu/~llynch/dnsop/index.html
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