Apache 2.4 'require host not' works but gives repeated AH01753 [authz_host:error] in apache error log

Question

Something is bothering me after my hosting provider went from Apache 2.2 to Apache 2.4.

I had these Apache 2.2 rules in my .htaccess

order allow,deny
    deny from domain.tld
    deny from 1.2.3.4
allow from all

Those rules went to 500's with Apache 2.4 so I've studied the Apache 2.4 manual and the web and finally came up with

<RequireAll>
Require all granted
    Require not host domain.tld
    Require not ip 1.2.3.4
</RequireAll>

I tested this with my own IP address and domain and this works, Apache gives a 403.  However, the Apache error log is coming up with

<Thu Dec 06 20:16:51.641853 2018> <authz_host:error> <pid 1347506:tid 140612011235072> <client 86.90.6.41:42035> AH01753: access check of 'domain.tld' to /index.html failed, reason: unable to get the remote host name

What is it saying there? Also, because I have more the one 'Require not host' rule in my htaccess, it is repeating this 'AH017053' error for every entry in my htaccess. It is doing so for every file requested by the visitor, so after index.html, it repeats this error for 'index.css' and such.

I would like this error to go away but I am at my wits' end how to. Also, I wonder, if Apache still is blocking my own IP address and domain name in a test situation, what is this error trying to say?

I've read https://httpd.apache.org/docs/2.4/mod/mod_authz_host.html and I am not sure, when Apache complains about 'AH017053', shouldn't I be able to look that up somewhere?

Answer 1

I've found the answer here https://httpd.apache.org/docs/2.4/mod/mod_authz_host.html

Instead of
Require not host domain.tld

It will stop attempting dual reverse lookups with
Require not forward-dns domain.tld

The reason for that is explained here https://httpd.apache.org/docs/2.4/mod/core.html#hostnamelookups