The Brute-force settings app should be included in a more current NC install by default and please consult the NC 16 Docs » Apps management to always ensure to not disable the Brute-force settings app inadvertently. IMHO fail2ban cannot be an alternative to the NC brute-force app and should be understood as an additional security effort.
Please be aware the fail2ban is not just “out of the box” nor “fire and forget”. To the opposite you have to check the setup and consider your security policy.
Usually, one has to enable certain filters in due deliberation as an educated sys admin.
Further reading:
- Bruteforce protection does not work as expected (only small delays) - #4 by TP75
- Fail2ban Native Support
- Brute-force testing: I can’t trigger it / Fail2Ban question
- What jails in fail2ban is safe to use?
There may be some better or some more …
Happy hacking.
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- Customers and Partners (mainly) closed portal — https://portal.nextcloud.com/
- An Enterprise Subscription from Nextcloud is available with email and phone support.
NOTE: Please be aware I am not affiliated with Nextcloud GmbH and my views are the free views as both a volunteer and a EU citizen and appear in a private capacity solely.