Description: If you operate your LANCOM router firewall with a deny-all strategy (information here  ) and you operate the LANCOM Content Filter, applications such as WhatsApp stop working properly. This document describes how to implement a remedy for this.
Requirements:
Procedure:In order to ensure that programs like WhatsApp continue to function where the LANCOM router firewall is operated with a deny-all strategy and the LANCOM Content Filter is operated at the same time, you need to configure explicit rules in the LANCOM firewall which allow the applications to communicate on other ports.
In the case of WhatsApp, these are the XMPP ports 5222 and 5223. 1) In LANconfig, open the configuration dialog for the LANCOM router and switch to the menu item Firewall/QoS → IPv4 rules → Rules. 2) Click on Add and create a new firewall rule which allows communication via the XMPP ports. 3) Select ACCEPT on the Actions tab. 4) In this example, all stations on the local area network may use the service. 5) On the Services tab, go to the section Protocols/target services, click add and select the option Create new service object from the context menu. 6) Give the new service object a name and go to the Services tab. 7) Enable the Custom protocols option and click the button Edit custom protocols. 8) Enter the XMPP ports 5222 and 5223 into the Ports field. 9) Close the dialog using the OK button and write the configuration back to the LANCOM router. 10) Communication via WhatsApp should work without problem now. | 
