Older Kerio Control versions hardcoded old IP ranges for the categorization servers. If those blocks were sold or changed, your firewall tries to reach dead IPs. This manifests as a "stuck hot" error where the service cycles between activating and failing.
Run the database configuration utility to disable automatic reliability tracking:
Resolving Web Filter Invalid authorization failures - KerioControl
: Zvelo key tokens expire every 21 days. If a token does not refresh properly through the standard internal server paths, authorization fails. Older Kerio Control versions hardcoded old IP ranges
When Kerio Control evaluates web traffic, it checks a dynamic global database to categorize and either allow or block URLs based on your internal rules. If this connection breaks, the firewall disables categorization to keep internet traffic flowing, rather than blocking the web entirely.
Redirect all DNS queries to a service like OpenDNS FamilyShield ( 208.67.222.123 and 208.67.220.123 ) or Cloudflare Gateway. This provides category-based filtering outside Kerio Control.
/etc/init.d/kerio-filtering stop
Log into Kerio Control via SSH and run the following command to turn off Reliability detection: cd /opt/kerio/winroute ./tinydbclient "update SiteFilter set DetectReliability=0" /etc/boxinit 5. Check Content Filter Rules Configuration
Kerio Control automatically disables the web filter if it fails to receive DNS responses from update servers 10 times in a row.
Is your license showing as or Expired on the dashboard? Run the database configuration utility to disable automatic
Ensure your firewall allows outgoing traffic on (HTTPS) and Port 80 (HTTP) for the firewall device itself.
Look for:
Note that the Web Filter is disabled by default for the Guest Interface to allow users to reach the welcome page without authentication. If this connection breaks