Question Block selected UserAgents for all vhosts

[Azurel]

I want block a few bots and crawlers, which not respect robots.txt.
I think the best way is to create a new apache config-file in "/etc/httpd/conf.d/block_useragents.conf" and reload apache?

Content of block_useragents.conf:

<Directory "/var/www/vhosts/">
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} ^(Agent1|Agent2|Agent3) [NC]
RewriteRule .* - [F]
</Directory>

Would this work for all vhosts? Is here a better way?

 

[OverWolf]

I think that Fail2Ban is very helpful for this use, and there is a pre-configured filter too.

 

[IgorG]

Instruction - Blocking extra bots using nginx

Very often our sites are visited by absolutely useless bots, which only create unnecessary load on the server. I don't understand why some people use .htaccess for this purpose because Apache consumes much more resources to solve this problem. In...

talk.plesk.com

 

[Cycs]

Instruction - Blocking extra bots using nginx

Very often our sites are visited by absolutely useless bots, which only create unnecessary load on the server. I don't understand why some people use .htaccess for this purpose because Apache consumes much more resources to solve this problem. In...

talk.plesk.com

Thanks for this link. Helps a lot.
BUT what about "missing" user-agents? In my log files I found dozens of requests with "no" or "unknown" user-agent. How to add this to the linked list?