nanog mailing list archives
Re: Comcast residential DNS contact
From: Grant Ridder <shortdudey123 () gmail com>
Date: Wed, 3 Dec 2014 09:54:03 -0800
Hi Everyone, Thanks for the replies! After reading them, i am doing some digging into DNS RFC's and haven't found much with respect to ANY queries. Not responding with full results to protect against being used in an attack makes sense. However, I find it odd that only 1 of the 4 anycast servers I tried would institute this. Also, as a side note, i hit all 4 anycast servers on both v4 and v6 with similar results already. -Grant On Wed, Dec 3, 2014 at 7:46 AM, Brian Rak <brak () gameservers com> wrote:
Shouldn't everyone be on IPv6 these days anyway ;) On 12/3/2014 10:28 AM, Jared Mauch wrote:So have A record queries. Do you filter those as well? Jared Mauch On Dec 3, 2014, at 9:08 AM, Stephen Satchell <list () satchell net> wrote:On 12/03/2014 04:04 AM, Niels Bakker wrote:* shortdudey123 () gmail com (Grant Ridder) [Wed 03 Dec 2014, 12:54 CET]:Both of Google’s public DNS servers return complete results every time and one of the two comcast ones works fine. If this is working by design, can you provide the RFC with that info?An ANY query will typically return only what's already in the cache. So if you ask for MX records first and then query the same caching resolver for ANY it won't return, say, any TXT records that may be present at the authoritative nameserver. This could be implementation dependent, but Comcast's isn't wrong, and you should not rely on ANY queries returning full data. This has been hashed out to tears in the past, for example when qm**l used to do these queries in an attempt to optimise DNS query volumes and RTT.At the ISP I consult to, I filter all ANY queries, because they have been used for DNS amplification attacks.
Current thread:
- Comcast residential DNS contact Grant Ridder (Dec 03)
- Re: Comcast residential DNS contact Niels Bakker (Dec 03)
- Re: Comcast residential DNS contact Grant Ridder (Dec 03)
- Re: Comcast residential DNS contact Niels Bakker (Dec 03)
- Re: Comcast residential DNS contact Stephen Satchell (Dec 03)
- Re: Comcast residential DNS contact Pavel Odintsov (Dec 03)
- Re: Comcast residential DNS contact Jared Mauch (Dec 03)
- Re: Comcast residential DNS contact Stephen Satchell (Dec 03)
- Re: Comcast residential DNS contact Jared Mauch (Dec 03)
- Re: Comcast residential DNS contact Brian Rak (Dec 03)
- Re: Comcast residential DNS contact Grant Ridder (Dec 03)
- Re: Comcast residential DNS contact Grant Ridder (Dec 03)
- Re: Comcast residential DNS contact Doug Barton (Dec 03)
- Re: Comcast residential DNS contact Grant Ridder (Dec 03)
- Re: Comcast residential DNS contact Mark Andrews (Dec 03)
- Re: Comcast residential DNS contact Grant Ridder (Dec 03)
- Re: Comcast residential DNS contact Niels Bakker (Dec 03)
- Re: Comcast residential DNS contact Andrew Sullivan (Dec 03)
- Re: Comcast residential DNS contact Christopher Morrow (Dec 03)
- Re: Comcast residential DNS contact Scott Helms (Dec 03)
- Re: Comcast residential DNS contact Livingood, Jason (Dec 03)