BIND and UDP tuning

[Lee]

On 9/30/18, Alex <mysqlstudent at gmail.com> wrote:
> Hi,
>
> On Sun, Sep 30, 2018 at 1:19 PM @lbutlr <kremels at kreme.com> wrote:
>>
>> On 30 Sep 2018, at 09:59, Alex <mysqlstudent at gmail.com> wrote:
>> > It also tends to happen in bulk - there may be 25 SERVFAILs within the
>> > same second, then nothing for another few minutes.
>>
>> That really makes it seem like either you modem or you ISP is interfering
>> somehow, or is simply not able to keep up.
>
> I'm leaning towards that, too. The problem persists even when using
> the provider's DNS servers.

Is this a personal project or can you get help from the network staff
& open trouble tickets with the various providers?

I'm making a big guess here, but you mentioned dnsbl.sorbs.net earlier so
$ dig dnsbl.sorbs.net.
   <.. snip ..>
;; ANSWER SECTION:
dnsbl.sorbs.net.        86400   IN      A       113.52.8.154
dnsbl.sorbs.net.        86400   IN      A       113.52.8.155
dnsbl.sorbs.net.        86400   IN      A       208.43.139.188
dnsbl.sorbs.net.        86400   IN      A       113.52.8.153
dnsbl.sorbs.net.        86400   IN      A       208.43.110.204

go here: https://wq.apnic.net/apnic-bin/whois.pl
and search for 113.52.8.154
which gives me
inetnum:        113.52.8.0 - 113.52.8.255
netname:        DIGITALSENSE
descr:          Digital Sense, Data Centres, Brisbane, Colocation
country:        AU

on the other hand
https://whois.arin.net/rest/net/NET-208-43-0-0-1/pft?s=208.43.139.188
gives ms
City	Dallas
State/Province	TX


If this is a packet drop issue as well as a personal project, you
might be stuck with figuring out just how fast you can send queries
before things start to break and adjusting your setup accordingly.

> I thought for sure I'd see some verifiable
> info from other people having problems with cable, such as from
> dslreports, etc, but there really hasn't been anything. The comment
> made about DOCSIS earlier in this thread was helpful.
>
> Do you believe it could be impacting all data, not just bind/DNS/UDP?
>
> Do people not generally use cable as even a fallback link for
> secondary services? I figured it was because there's no SLA, not
> because it doesn't work well with many protocols.

I think it's more of a you pay for what you get thing.  "business
class" cable costs more & might even be provisioned better, but at
least the first question you get when calling support isn't "have you
tried turning it off and on?"

wrt your earlier
  I attempted to search github for query.c line 8580
there's probably a github answer; I went to https://ftp.isc.org/isc/bind9/
found my release and downloaded the BIND-xxx.tar.gz source code file.

It'd be nice if ISC made no response to a query a separate error vs.
lumping it in with all the other "Something has gone wrong."
possibilities.

Lee