I have configured and applied firewall rules using Plesk Firewall Extension, but after server reboot I have found that it has not been saved.
Such behaviour is considered to be a software issue #PPPM-1724 and will be fixed in future product updates.
Please use provided ID to track maintenance in Parallels Plesk release notes.
Subscribe to our knowledge base - each product update comes with corresponding KB article:
Note: the issue is actual only for Debian-based systems and has been fixed in Plesk Panel 12
As a workaround it is possible to change Plesk firewall configuration script:
Backup original file:
# cp /opt/psa/var/modules/firewall/firewall-emergency.sh /opt/psa/var/modules/firewall/firewall-emergency.sh.orig
Modify the original file with text editor (for example, vi) /opt/psa/var/modules/firewall/firewall-emergency.sh in order remove string:
-rm -f /opt/psa/var/modules/firewall/active.flag