You created a dynamic DNS hostname and ran an IP update utility to map the static hostname to your dynamic IP. However, you cannot ping the hostname. Is the dynamic DNS service not working? Not necessarily. Here are a few common reasons:

• DDNS update
• DNS propagation delay
• Firewall/Router configuration

What is ping?

Ping is a simple network tool that sends ICMP (Internet Control Message Protocol) packets from the source to the destination host. If the target host is accessible, it sends packets back. The following is the output of the ping utility (run on a Windows computer). 4 packets are sent to the destination host (google.com). The ping result shows a combination of the correct IP being resolved through a DNS resolver, successful ICMP echo reply, and completion of a single ping test (minimum, maximum, the mean round-trip times and standard deviation of the mean).


DDNS update

If the DDNS hostname is not responding to ping. You can first check if it is mapped to the correct IP address. If the DDNS hostname is mapped to your current IP, then the DDNS service is working correctly. If you are using your own domain such as yourname.com, please be sure to list Dynu name servers at the domain registrar so that your domain resolves to the IP returned by Dynu DNS servers.

DNS propagation delay

It takes time for the IP changes to propagate across the internet after DDNS updates them, especially if your domain has a long TTL. This can cause temporary ping issues. You can run a DNS propagation test using our Network Tool.

Firewall/Router configuration

Firewall or router settings might be blocking ICMP requests (which ping uses), preventing you from reaching the device. This is by far the most common cause of the ping issue. In this case, not only are you unable to ping the hostname, you also cannot ping the IP address, which indicates an issue with the router/firewall settings of the target host instead of DDNS updates or mapping.