An openvpn package is now available on Synology Website. After the openvpn package is installed, the configuration file is located here : /usr/syno/etc/synovpn/openvpn/openvpn.conf Add the following line in the configuration file : push "dhcp-option DNS 192.168.1.3" where ip address is your DNS server ip address. Restart the openvpn package.