Issue False Failed Login from Plesk 360

[se2e-dev]

Server operating system version

Debian 12.11

Plesk version and microupdate number

18.0.71 Update 2

At intervals of approximately 30 minutes, the following entry is recorded in the Action Log:

2025-08-09 15:08:18 ERR panel [Action Log] Failed login attempt with login '<invalid>' from IP 34.254.37.129

According to the official Plesk 360 documentation, this IP address belongs to Plesk 360 servers:
360 FAQ - Documentation

The connection originates from a trusted source but is registered by the system as a failed login attempt. This leads to a continuous increase of irrelevant log entries and, in combination with Fail2Ban, can result in blocking the IP unless it is placed on a whitelist.

Clarification of this behavior and the provision of either a fix or a configuration option is required to prevent unnecessary log entries and false blocks.

This issue has only started occurring recently. Previously, connections from the Plesk 360 IP were not logged as failed login attempts.

 

[AYamshanov]

Hi,

I have asked the team for ideas and suggestions. Here are some recommendations...

The symptoms are similar to a connection failure between Plesk 360 and the Plesk server. Considering that P360 attempts to ping the server every 30 minutes, the server has been added to P360, which means that the more likely cause of the failure is that someone has removed the API keys (to list keys: plesk bin secret_key -l) for synchronization with P360 from the Plesk server.

It can be fixed by removing the server from Plesk 360 (and removing data related to connection connection on Plesk side) and adding the server to Plesk 360 back:
1. Remove server from Plesk 360:
https://support.plesk.com/hc/en-us/articles/13303695712791-How-to-remove-a-server-from-Plesk-360
2. Remove connection from Plesk side (see via SSH part)
https://support.plesk.com/hc/en-us/articles/13303696715415-The-Monitoring-page-in-Ple[…]360-Monitoring-The-server-does-not-exist-in-Server-Inventory
# plesk ext platform360 --delete-connection
Then try to add the server again with Plesk 360. If you face an error, it makes sense to search in KB and check /var/log/plesk/panel.log. We have solutions for most of the known issues: https://support.plesk.com/hc/en-us/categories/13303524328855-Platform-360