[BALUG-Admin] excess NOTIFY (about ever 90s) ISC BIND 9.18.24 ...

Sat Jun 8 23:31:25 UTC 2024

So, haven't 100% gotten to the bottom of the excess NOTIFY,
but it is apparently present in ISC BIND 9.18.24 and some other versions,
and Debian bind9 1:9.18.24-1 which is the current version for the current stable
Debian 12 bookworm.  Also thinking that bug, for Debian stable, probably
doesn't make it to >=important priority (probably just priority normal),
so probably won't get fixed in the current stable.
Thus far, this is what I've run across that seems most informative about it:
https://gitlab.isc.org/isc-projects/bind9/-/issues/3242
So, workarounds?  I'm not going to be upgrading that host from stable
for quite some time (most likely year(s)), and other alternatives to fixing it
on the server side is probably more additional overhead than I'm likely to
want to bother with - so probably not going there.
On the client side, can reconfigure logging to not log those bits,
or possibly ignore them (e.g. by filter) in whatever
notifications/reporting one is doing.
So, yes, it is definitely coming from the nameserver itself, and all indications
are it's a bug.  I did see some chatter somewhere about it possibly being a
but only if client doesn't respond in some way(s)?  But that's not what I see
in my testing on clients that do respond as expected, so I don't think that's
it at all - at least in my case.

Oh, as for possibly adjusting the logging on [ns1.]linuxmafia.com,
I notice it's got
bind9 version 1:9.7.1.dfsg.P2-2
installed, and yes, also has
bind9-doc version 1:9.4.2-4,
but that's different version.
However, it does have, in /var/cache/apt/archives/
bind9-doc_9.7.1.dfsg.P2-2_all.deb
So, that would be the corresponding documentation package,
which could be installed, or the files simply extracted from that and
consulted as may be desired.  Anyway, within that, around:
doc/bind9-doc/arm/Bv9ARM.ch06.html#id2575303
It has information about configuring logging, what the defaults are
and the category
notify
in logging configuration that one can use to adjust what one
does/doesn't want done regarding logging of
notify
activity.

And, along the way, I've also rather well updated:
Debian wiki: DNSSEC Howto for BIND 9.9+:
https://wiki.debian.org/DNSSEC%20Howto%20for%20BIND%209.9+
And also well whipping mpaoli.net (and nameserver in general) configuration
into shape for the current Debian stable.

If I find anything else particularly noteworthy about the notify situation,
I'll update.

On Tue, Jun 4, 2024 at 4:21 PM Michael Paoli <michael.paoli@berkeley.edu> wrote:
>
> There's two different issues (well, three, but 3rd is minor), not to
> be confused:
>
> The second - unrelated - issue.  I've got excess notifies being sent
> from my server(s).
> Now, not at all unusual that sometimes there may be bursts of activity
> and updates and such,
> at least some of that is to be expected.
> What's quite unexpected and ought not be happening, but is,
> is I've got server sending frequent (e.g. like every 90 seconds-ish -
> or so) notifies
> when basic zone DNS data hasn't changed - same SOA serial, etc.
> So, something's still amis with that which I need to correct (doesn't
> really break any
> functionalities ... but rather wasteful all those excess notifies being sent,
> also tends to cause needless traffic on both sending side,
> and receiving servers checking and finding they've got nothing
> to do because they're already current).
> And, as I'd earlier mentioned, I suspect from some major upgrades I did
> a few weeks ago ... well, that was off-list, so, let me include fair
> bit more of it here
> (but not the whole thing, it gets very long, especially with all the
> earlier referenced):
> -----
> ---------- Forwarded message ---------
> From: Michael Paoli <michael.paoli@berkeley.edu>
> Date: Mon, Jun 3, 2024 at 11:19 PM
> Subject: Re: [BALUG-Admin] (forw) linuxmafia.com 2024-06-03 15:02 System Events
> To: Al <aw009@sunnyside.com>
> Cc: Rick Moen <rick@linuxmafia.com>
>
> Yeah, ... something's still not quite right there.
> Did upgrade on that host/server a couple weekends ago
> Debian: buster 10 --> bullseye 11 --> bookworm 12
> $ TZ=GMT0 stat -c '%z %Z %n' /etc/debian_version
> 2024-05-14 07:37:15.000000000 +0000 1715672235 /etc/debian_version
> $
> Some of ye olde(er) DNS configuration options, while still
> (marginally?) functional, are quite deprecated, and I'm getting
> warnings on that and one other minor issue ... anyway, need to do
> some cleanup/reconfig with DNS server on that host.
> Should all be fine after that.  Functional in the meantime, but ...
> not yet optimal ... clearly.
>
> On Mon, Jun 3, 2024 at 10:43 PM Al <aw009@sunnyside.com> wrote:
> >
> > I'm probably not reading those logs right but part of it looked like mpaoli was being signed every minute?  Only partial logs, not enough to be sure.  7:28, 7:29.
> > Just a thought...
> >
> > On June 3, 2024 20:15:06 Michael Paoli via BALUG-Admin <balug-admin@lists.balug.org> wrote:
> >
> >> Well, under some circumstances, I'd expect a relative flury, or
> >> "bursts" of notify
> >> activity.  E.g. I do TLS(/"SSL") certs via LetsEncrypt.org (LE), using DNS
> >> verification.  Some/many of those certs will have multiple
> >> Subject Alternative Name (SAN) domains, and there may be fair number
> >> of such certs.  So, adding the relevant records for verification, and then
> >> removing them after having obtained the issued cert(s) - that can be a
> >> fair burst of activity.  But those generally wouldn't persist over a long
> >> period of time.  E.g. every 90 seconds over many hours or days
> >> or more ... then something else is going on.  So ... let me dig
> >> (pun not quite intended but apt) a bit more and peek what's currently
> >> goin' on there ...
> ...
> ----- End forwarded message -----
> -----
> I suspect it has to do with some changes in how DNSSEC is configured,
> most notably a configuration syntax I'm using is (now) quite deprecated,
> and it may be thus defaulting to some rather undesirable behavior(s)
> which may include triggering the excess notifies.
> Anyway, want to test it carefully and not break things, that's why I'm not
> willy-nilly throwing things at it.  Goals being, to not only fix it, but if
> feasible without causing further breakage along the way, and also not
> disabling DNSSEC at any point (shouldn't need to) ... and while I'm at
> it, also reviewing and checking/updating earlier documentation (much of which
> I wrote):
> Debian wiki: DNSSEC Howto for BIND 9.9+:
> https://wiki.debian.org/DNSSEC%20Howto%20for%20BIND%209.9+
> And, along the way, I've also got temporary zone and subdomain I'm
> fiddling with: tmp.mpaoli.net. to test things, etc.  Anyway, it's still a work
> in progress to get that all squared away (get issue fixed, not further
> break things,
> and update relevant documentation).
> Anyway, as far as I'm aware, the excess notifies being sent don't have
> anything to do with the Comcast issues.
>
> On Tue, Jun 4, 2024 at 3:12 PM Rick Moen <rick@linuxmafia.com> wrote:
> >
> > More of same, involving back-to-back NOTIFY traffic about mpaoli.net,
> > allegedly originating from master nameserver 96.86.170.226 .  Michael, I
> > greatly doubt your nameserver is doing this.  mpaoli.net's zonefile is
> > pretty unchanging.  I suspect Comcast middleman fsckery.  Thoughts?
> >
> > ----- Forwarded message from logcheck system account <logcheck@linuxmafia.com> -----
> >
> > Date: Tue, 04 Jun 2024 02:02:01 -0700
> > From: logcheck system account <logcheck@linuxmafia.com>
> > To: root@linuxmafia.com
> > Subject: linuxmafia.com 2024-06-04 02:02 System Events
> >
> > System Events
> > =-=-=-=-=-=-=
> > Jun  4 01:47:15 linuxmafia named[15622]: zone mpaoli.net/IN: Transfer started.
> > Jun  4 01:47:15 linuxmafia named[15622]: transfer of 'mpaoli.net/IN' from 96.86.170.226#53: connected using 96.95.217.99#52012
> > Jun  4 01:47:15 linuxmafia named[15622]: zone mpaoli.net/IN: transferred serial 1717468800
> > Jun  4 01:47:15 linuxmafia named[15622]: transfer of 'mpaoli.net/IN' from 96.86.170.226#53: Transfer completed: 1 messages, 6 records, 546 bytes, 0.064 secs (8531 bytes/sec)
> > Jun  4 02:00:09 linuxmafia named[15622]: zone mpaoli.net/IN: Transfer started.
> > Jun  4 02:00:09 linuxmafia named[15622]: transfer of 'mpaoli.net/IN' from 96.86.170.226#53: connected using 96.95.217.99#57758
> > Jun  4 02:00:09 linuxmafia named[15622]: zone mpaoli.net/IN: transferred serial 1717491608
> > Jun  4 02:00:09 linuxmafia named[15622]: transfer of 'mpaoli.net/IN' from 96.86.170.226#53: Transfer completed: 1 messages, 15 records, 1266 bytes, 0.072 secs (17583 bytes/sec)