nanog mailing list archives
Re: DNS resolver reaction to non-reachable authoritative DNS server
From: Doug Barton <dougb () dougbarton us>
Date: Thu, 13 Mar 2014 10:28:24 -0700
On 03/13/2014 12:35 AM, Anurag Bhatia wrote:
Hello there! I am trying to troubleshoot a case of DNS failure issue with one of Indian Govt's domain (nic.in). I can see that 1 out of 4 authoritative DNS server is IPv6 only. We have quite a few users running IPv4 only setup and hence 1/4 of these DNS servers are non-reachable from the recursor hosted by our clients. How is DNS query expected to respond in such case? Will it give SRVFAIL and terminate immediately (causing DNS resolution failure) OR it will just see one of the auth DNS as non-reachable and next will proceed with either of other three thus slowing down but with no failure?
Basically the latter.If your customers are using BIND there is a flag you can supply to named to cause it to operate only in IPv4. That would avoid this problem altogether.
hope this helps, Doug
Current thread:
- DNS resolver reaction to non-reachable authoritative DNS server Anurag Bhatia (Mar 13)
- Re: DNS resolver reaction to non-reachable authoritative DNS server Doug Barton (Mar 13)
- Re: DNS resolver reaction to non-reachable authoritative DNS server Mark Andrews (Mar 13)
- Re: DNS resolver reaction to non-reachable authoritative DNS server Doug Barton (Mar 13)
- Re: DNS resolver reaction to non-reachable authoritative DNS server Anurag Bhatia (Mar 14)
- Re: DNS resolver reaction to non-reachable authoritative DNS server Mark Andrews (Mar 13)
- Re: DNS resolver reaction to non-reachable authoritative DNS server Doug Barton (Mar 13)