Heimdal security uses 3 ports in order to provide the security filter.
The ports are the following:
- Port 53 - is used by Heimdal to apply the DNS (127.0.0.1)
- Port 443 - is used by Heimdal to filter HTTPs
- Port 80 - is used by Heimdal to filter HTTP
For exception that needs to be added in Firewall, click HERE