[clamav-users] Freshclam "Can't query daily" due to DNS issue

[Robert L Mathews]

For a few days, I've been seeing new messages like this in the logs,
once per day per server:

freshclam[1133]: Sat Jul 27 01:49:03 2019 -> *Can't query
daily.25523.93.1.0.2606470000000000000000006810da54.ping.clamav.net

Some investigation suggests that this is failing because ns1a.clamav.net
(etc.) have DNS NS records delegating *.ping.clamav.net to
"ns4.clamav.net", but ns4.clamav.net does not work.

Sample:

----------------------------------------------------------------

$ dig +norecurse ping.clamav.net NS @ns1a.clamav.net.
...

;; QUESTION SECTION:
;ping.clamav.net.    IN  NS

;; AUTHORITY SECTION:
ping.clamav.net.  86400  IN  NS  ns4.clamav.net.

;; ADDITIONAL SECTION:
ns4.clamav.net.    3600  IN  A  12.167.151.33

;; Query time: 68 msec
;; SERVER: 198.148.79.38#53(198.148.79.38)


$ dig +norecurse
daily.25523.93.1.0.2606470000000000000000006810da54.ping.clamav.net
@ns4.clamav.net
...

;; connection timed out; no servers could be reached

----------------------------------------------------------------

I don't think this is just me, because these third-party tests also fail:

http://dns.squish.net/traverses/8d77e0b0f6a40da697ad7db180c99563/detail
("83.3% Query timed out at ns4.clamav.net (12.167.151.33))"

https://mxtoolbox.com/SuperTool.aspx?action=a%3adaily.25523.93.1.0.2606470000000000000000006810da54.ping.clamav.net&run=toolpage
("DNS No Valid NameServers Responded")

-- 
Robert L Mathews, Tiger Technologies, http://www.tigertech.net/