Enable SSH in Control Panel / Terminal & SNMP / Terminal.Install Java, version 1.7.0, using the Java Manager Package in the Package Center of you Synology NAS.Log into your Synology NAS admin GUI as administrator.Use an upstream DNS server, also for queries originating from within the NAS.Use UpStart jobs to start up NxFilter automatically after boot.Modify the Synology firewall to accept traffic for DNS and the NxFilter admin GUI.Add kernel modules for port redirection from Port 53 to a non-privileged port, to avoid running the DNS server as root.(at least temporarily) enable SSH on your NAS.However, to make it safe (that is, not running it as root) was a little more involved as I thought… You will need to… Thus I decided to go down the native way with the Java Manager module. Unfortunately it is not able to run Docker containers. The DS115j is one of the more affordable models, running Version 5 of the Synology DiskStation Manager (DSM).

To free up my other Raspberry Pi from being a DNS server and to use an already existing NAS on my local LAN, I decided to try to install NxFilter (my favourite DNS filtering solution) to a Synology DS115j NAS device.

Nxfilter group