Fail2ban plugin is not working properly.

I installed the fail2ban plugin in early 2022 to create a nextcloud jail. I left it alone after confirming that blocking access to the site worked normally.

I recently installed vaultwarden to create a vaultwarden jail and tested it to see if it works normally, but I only received an email from fail2ban saying that access from the test ip was blocked, but access to the site from the ip was not blocked. I was still able to access the site with the blocked ip.

The nextcloud and vaultwarden jails I created are all the same, and the default omv gui jail also gives the same error.

I tried reinstalling the plugin but it's the same.

After searching on the forum here, I tried using the command related to omv salt, but the error still occurs.

Nextcloud and vaultwarden run in a docker environment and are accessed through a reverse proxy.

I am new to linux environment and server.

[environment]

G4560, 8GB RAM, omv iso installed

[Related settings]

Status

|- Number of jails: 1

`- Jail list: nextcloud

Status for the jail: nextcloud

|-Filter

| |- Currently failed: 0

| |- Total failed: 0

| `- File list: /var/lib/docker/volumes/nextcloud_data/_data/nextcloud.log

`-Actions

|- Currently banned: 1

|- Total banned: 1

`- Banned IP list: "TEST IP"

[Related logs]

fail2ban.utils [2055511]: ERROR 7f73775e78f0 -- exec: iptables -w -N f2b-vaultwarden

fail2ban.utils [2055511]: ERROR 7f73775e78f0 -- stderr: "iptables v1.8.7 (nf_tables): invalid port/service `' specified"

fail2ban.utils [2055511]: ERROR 7f73775e78f0 -- stderr: "Try `iptables -h' or 'iptables --help' for more information."

fail2ban.utils [2055511]: ERROR 7f73775e78f0 -- returned 2

fail2ban.actions [2055511]: ERROR Failed to execute ban jail 'vaultwarden' action 'iptables-multiport' info 'ActionInfo({'ip': 'TEST IP', 'family': 'inet4', 'fid': at 0x7f73776beca0 >, 'raw-ticket': at 0x7f73776bf3a0>})': Error starting action Jail('vaultwarden')/iptables-multiport: 'Script error'

pavelkms

After creating jail.local in /etc/fail2ban path

[DEFAULT]

chain=DOCKER-USER

I pasted the above and rebooted the system.

But nothing has changed.

After unblocking all IPs, I tried blocking again, but access from the blocked IP is still possible.

I tried sudo iptables -L

but I don't see any blocked ips.

It seems that the ip is not registered in iptables due to a script error.