Fail2Ban is installed and enabled in Plesk
When opening Plesk or a website or logging in to an email account from a specific IP address (for example, 203.0.113.2), the connection fails:
Can't reach site
This site can’t be reached
203.0.113.2 took too long to respond.
From other IP addresses Plesk, websites and email accounts are accessible
The IP address 203.0.113.2 can be found in Plesk at Tools & Settings > IP Address Banning (Fail2Ban) > Banned IP Addresses or via CLI:
# plesk bin ip_ban –banned
Banned IP addresses:
203.0.113.2 plesk-panel Jan 1, 2020
Some operations in Plesk might fail with the error:
PLESK_ERROR: Request to backend API failed with error: Network error
The user’s IP address has been banned by Fail2Ban.
Unban the IP-address or add it to trusted IP-addresses
Unbanning the blocked IP address via Plesk
Note: It should be accessed from a different IP address (another device).
Go to Tools & Settings > IP Address Banning (Fail2Ban) > Banned IP Addresses
Select the user’s IP address and click Unban or Move to Trusted IPs
Unbanning the blocked IP address via a command-line interface
Connect to the Plesk server via SSH
Unban the user’s IP address:
# plesk bin ip_ban –unban 203.0.113.2
SUCCESS: The selected IP addresses were unbanned.
Add the IP address to the list of trusted IP addresses:
# plesk bin ip_ban –add-trusted 203.0.113.2