FAQ - What’s the Use of the Configuration Port?
Port 1 of the card in slot 1 (leftmost) is assigned to IP net 1 (configuration network) in default settings (for routers with 5-port switch; for routers with 2-port switch, port ETH1 is assigned to IP net 1). This local network has the static IP address 192.168.1.1. It is intended for accessing the router from a configuration PC. The firewall rules for HTTP (port 80) and HTTPS (port 443) access are also entered for this in default settings.
It is recommended to use IP nets 2-5 and the other ports for the application to still enable local configuration access to the router. If the application’s requirements or other circumstances do not allow this, port 1 can also be configured accordingly like ports 2-5. It should be ensured that router access in case of an emergency is still possible using other means.