The use of DynDNS services always involves the risk that the accessibility and availability of network resources is entrusted to an external service provider, and the owner can no longer guarantee that these resources are continuously available. For this reason, we recommend that you minimize risk by creating redundancies and using other mechanisms: Use a fixed IP address (if available). Use an additional DynDNS provider to provide redundancy in case of failure. For VPN connections, an additional DynDNS address should be entered as a surplus gateway. In the action table of the LANCOM router, create an e-mail notification about the change of address. If problems should arise with updates by several DynDNS providers, you should check to see if the problem lies with the communication between the LANCOM router and the DynDNS service, or whether the problem is with the DynDNS provider itself. The use of DynDNS update software is ideal for this situation.