In message <01c201caaead$b115eda0$1341c8e0$@nl>, "Mark Scholten" writes:
-----Original Message----- From: marka@isc.org [mailto:marka@isc.org] Sent: Tuesday, February 16, 2010 12:37 AM To: Mark Scholten Cc: 'Tony Finch'; nanog@nanog.org Subject: Re: in-addr.arpa server problems for europe?
In message <017901caae69$5d9e8770$18db9650$@nl>, "Mark Scholten" writes:
-----Original Message----- From: Tony Finch [mailto:fanf2@hermes.cam.ac.uk] On Behalf Of Tony Finch Sent: Monday, February 15, 2010 6:21 PM To: Mark Scholten Cc: nanog@nanog.org Subject: RE: in-addr.arpa server problems for europe?
On Mon, 15 Feb 2010, Mark Scholten wrote:
I've seen problems that are only there because of DNSSEC, so if
there
is a
problem starting with trying to disable DNSSEC could be a good idea. As long as not all rootzones are signed I don't see a good reason to use DNSSEC at the moment.
You realise that two of them are signed now and the rest will be signed by 1st July?
Tony.
Yes, I realise that. I also realise that not all nameserver software can work as it work with DNSSEC. That is also a problem that has to be solved and for as far as I know all nameserver software we use support it or will support it in the future. As long as it is not supported by all nameserver software you can keep problems.
Nameservers that are not DNSSEC aware will not get responses that contain DNSSEC records unless a client explicitly requests a DNSSEC record type or make a * (ANY) request.
There is no problem to solve. Just a lot of misunderstanding.
That said the majority of nameservers on the planet are DNSSEC aware and will request the DNSSEC record to be returned. They will also fall back to plain DNS if middleware blocks the response.
As you've understood I need to read something extra about DNSSEC support. The most things I know about DNSSEC are based on my contacts with software writers that create nameservers and system administrators maintaining multiple nameservers. So if I understand it correctly; if a resolver requests DNSSEC information (together with for example www.domain.tld) and 1 resolver before the AUTH nameserver doesn't have DNSSEC it won't ask/require DNSSEC? In that case men in the middle attacks are still possible. Also note that a provider might have multiple resolvers with some using/able to provide DNSSEC and others without DNSSEC support.
Mark
DNSSEC requires a DNSSEC clear path between the validator and the authoritative servers. If there is not a DNSSEC clear path the answers will be rejected as they cannot be validated. A man in the middle can launch a denial of service attack but cannot launch a spoofing attack. Most validators, at the moment, are co-located with iterative resolvers which provide the DNSSEC clear path. Some applications are fully DNSSEC aware and do their own validation in which case there needs to be a DNSSEC clear path to the recursive resolver and onwards to the authoritative servers. Other applications are only AD aware, in which case they trust the recursive resolver and need channel security between the application and the recursive resolver. Mark -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: marka@isc.org