Question:
IP addresses are being banned by Fail2Ban on a Plesk server when working from Email Client
Symptoms
- When sending/receiving messages from Email Client (such as Outlook), the user's IP address is blocked by Fail2Ban
- 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
Cause
The user IP address has been banned by fail2Ban "recidive" and "plesk-dovecot" jails because Email client actions are triggering false-positives on fail2ban.
Resolution
- Apply one of the following solution
s:
- Adjust fail2ban settings ban period and number of attempts before the ban to mitigate such false-positives: How to change the Fail2ban ban period and the number of attempts before the ban in Plesk?
Add client IP to trusted IP-Addresses:
Note: With the following solution, the problem may reoccur in case the client IP address will change.
- Connect to the server via SSH with a different IP address
- Open Tools & Settings > IP Address Banning (Fail2Ban) > Trusted IP Addresses > Add Trusted IP
- Add the IP address to be trusted in the text field IP address and click OK
[/list]