johnmill at brandeis.edu
Tue Aug 16 15:11:53 UTC 2016
On Mon, Aug 15, 2016 at 11:23 PM, blrmaani <blrmaani at gmail.com> wrote:
> From tcpdump, it appears that customers are receiving delayed response and are too sensitive for timeouts.
> The queries they are sending are authoritative i.e the zone is on our nameserver.
> How do I trouble-shoot this issue? This is really intermittent and hard to reproduce..
I'm a little confused: if your clients are _sending_ queries, they're
either sending recursive queries, or they're acting as nameservers
themselves and are sending iterative queries, following delegation to
resolve names outside of your domain.
If your clients are _replying_ to queries, then they are acting as
authoritative nameservers--answering queries for records in your
To dig into things further, nameserver logs and errors would be
helpful, as would your config. You might also consider doing a
selective packet capture on your nameservers for the clients that are
If you haven't already, I highly recommend picking up a copy of Albitz
and Liu's _DNS_and_BIND_: it's a bit dated, but still a good
introduction to the basics of BIND.
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