Synology with Pi Hole, DNS problems

Synology with Pi Hole, DNS problems

After setting up Pi Hole i noticed the Synology NAS in the network had trouble with DDNS, it was however quickly resolved.

Synology’s Quickconnect, using Dynamic DNS (DDNS), will automatically update a DNS address (domain) to the (public) IP in front of your NAS. This is useful when you have a dynamic IP from your ISP, hence changes, as most residential connections have. Without DDNS you would have to update your DNS record every time you get assigned a new IP from your ISP; laborious. Or buy a connection with a static IP address; usually more costly.

After running Pi Hole the NAS stopped sending emails, error: failed to resolve host address, and stopped updating the Quickconnect address with the real public IP address of my home connection; error: failed to get external IP.


Synology has a troubleshoot guide for when the Quickconnect fails.

While the exact reason it fails is not clear to me, and Synology does a good job hiding the error details, the first suggestion worked: manually specifying the DNS server. Go to Control Panel > Network > General and tick the Manually configure DNS server checkbox. Set the Preferred DNS server to the IP of the device running Pi Hole. Leave the Alternative DNS Server blank or your favorite external DNS server.

Does not even require a restart.

Noticed an error in this post? Corrections are appreciated.

© Nelis Oostens