How to install / configure IPv6 openVPN server

1. In the Synology Package Center install "VPN Server"
2. Setup a dyndns name:
  • Preferred option via Synology built-in DDNS:
  • Open Control Panel, click on External Access, under DDNS tab click on Add 

3. Enable DHCPv6 prefix domain

  • Open Control Panel, click on Network, under Network Interface select your LAN connection and click Edit
  • Under IPv6 tab select IPv6 setup DHCPv6-PD 

Remark: With DHCPv6-PD (prefix delegation), a delegating router (e.g. FritzBox) delegates IPv6 prefixes to a requesting router (e.g. Synology VPN Server). The requesting router then uses the prefixes to assign global IP addresses to the devices on the subscriber LAN

Example for Fritzbox 6490:

  1. In the menu select Home Network, Network
  2. Under Network Settings tab scroll down to IP Addresses and click on IPv6 Addresses on the right side
  3. Scroll down to DHCPv6 Server in the Home Network and check Assign DNS server, prefix (IA_PD) and IPv6 address (IA_NA)

4. Configure openVPN

  1.  In Package Center OPEN VPN Server
  2.  In the left menu click on OpenVPN 
  3.  Enable OpenVPN Server
  4.  Set Protocol to TCP
  5.  Select Enable IPv6 Server mode 
  6. Optional: Check allow clients to access server’s LAN 
  7.  Select the IPv6 prefix you previously set up.
  8. Click Apply

5. Firewall

Configure your internet router firewall (and the Synology firewall if needed) to allow TCP port 1194