Unable to open Plesk or a website or log in to an email account from a specific IP address: ERR_CONNECTION_TIMED_OUT

Kuzma Ivanov

Updated January 13, 2026 19:01

Plesk for Linux kb: technical ABT: Group B

Applicable to:

Fail2Ban is installed and enabled in Plesk.
When opening Plesk or a website or logging in to an email account via webmail from a specific IP address (for example, 203.0.113.2), the connection fails:

CONFIG_TEXT: ERR_CONNECTION_TIMED_OUT

CONFIG_TEXT: ERR_CONNECTION_REFUSED

CONFIG_TEXT: 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 following error message may appear in Plesk during some operation:

PLESK_ERROR: Request to backend API failed with error: Network error
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

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

Log in to Plesk 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

To find out why an IP address got banned by Fail2Ban, see this KB article.