OARC's Open DNSSEC Validating Resolver

7 June 2011 UPDATE: The .de zone is now fully signed and the corresponding DS Resource Record has been added to the root zone, so the testbed redirection has been removed from both resolvers.

4 October 2010 UPDATE: We have now added the .de DNSSEC Testbed to both resolvers.

How To Use ODVR

OARC is pleased to offer open DNSSEC-validating resolvers ("ODVR") that anyone can use to experiment with DNSSEC. The IP addresses for ODVR nameservers are:

Instance   IPv4   IPv6
BIND 9   149.20.64.20   2001:4f8:3:2bc:1::64:20
Unbound   149.20.64.21   2001:4f8:3:2bc:1::64:21

You might like to manually query the ODVR nameservers with a tool such as dig. Be sure to add the +dnssec option:

$ dig +dnssec @149.20.64.20 iis.se | less

The AD bit in the response flags tells you that the reply data has been validated:

;; flags: qr rd ra ad; ...

Another way to use ODVR is to place the following lines in your Unix /etc/resolv.conf file:

nameserver 149.20.64.20
nameserver 149.20.64.21

Windows users can manually set DNS servers in the Internet Protocol Properties dialog of a network connection.

Trust Anchors

ODVR has been configured with the following list of trust anchors:

ZoneKey VerifiedPGP Sig Verified
.YESYES
adnono
iqnono
lrnono
manono
sjnono
vcnono
xn--fzc2c9e2cnono
xn--xkc2al3hye2anono

ODVR also validates against ISC's DLV registry.

Data Collection

OARC collects data from the ODVR nameservers and makes this data available to our members for research purposes.

Traffic Graphs

These graphs, updated nightly, show the number of queries received with and without the "DO" bit set, and the number of responses sent with and without the "AD" bit set.

Configuration Files

BIND: UNBOUND:

Frequently Anticipated Questions

Q: Does it mean all my DNS lookups are secure if I use OARC's validating resolvers?

A: No, probably not, for the following reasons:

  1. Most zones are not yet signed. Chances are that, for most of your DNS queries, there will not be any DNSSEC signatures. However, we expect this to improve over time as more and more zones take advantage of DNSSEC.
  2. Most end-user applications (think Web browser) and stub resolvers (a part your computer's operating system) do not yet perform DNSSEC validation. This means that the channel between you and the OARC nameserver is still vulnerable to attack. In other words, security of the DNSSEC transaction is only guaranteed up to the point where the validation has been performed.

Q: Then why are you doing this?

A: A few reasons:

  1. So that you can play with DNSSEC without changing the configuration of your own nameserver.
  2. To convince you that a DNSSEC-validating resolver works almost exactly like a non-validating resolver and that you should go ahead and enable DNSSEC on your own resolvers.
  3. To collect and publish data on adoption of DNSSEC over time.

Q: Can I use ODVR nameservers provide protection from Kaminsky-style spoofing attacks?

A: The answer is complicated and depends on a number of other factors. Generally, this should not be your motivation for using ODVR. If you are stuck using a DNS resolver with poor source port randomization then ODVR may make you more secure. However, a determined attacker could probably spoof answers that appear to come from the ODVR nameservers and give you bad answers.

Q: I thought open resolvers were a bad thing?

A: It's true that open resolvers are usually considered to be a problem and have been used — in combination with source address spoofing — to conduct large-scale DDoS attacks. Such attacks are made possible because (1) there are hundreds of thousands, if not millions, of open resolvers, and (2) their owners/operators are unaware of the openness. The ODVR nameservers are rate-limited and closely monitored. If we have reason to suspect abuse of the ODVR nameservers, we will act quickly to stop it. Please contact the OARC Admin if you have abuse concerns.

Q: Can DNS-OARC members have non-rate-limited access?

A: Absolutely. Write to the OARC Admin to find out how.

Submitted by admin on Tue, 2008-10-28 21:13. categories [ ]