Synology has added L2TP/IPSec as an option for a VPN.
I’ve never been able to get it to work on a Windows client until today.

Ports Required:

  • IPSec – UPD 500
  • IPSec NAT Traversal – UDP 4500
  • L2TP – UDP 1701

Fix on Windows clients – http://support.microsoft.com/kb/926179

  • For Win7 and Win8 Machines
    • HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesPolicyAgent
    • New DWORD (32-bit) – AssumeUDPEncapsulationContextOnSendRule
    • Set the Value Data to 2

Update:

Using OpenVPN with port 443, for easier access: http://forum.synology.com/enu/viewtopic.php?t=45545#p215354

 

Article comes from:

https://www.rebelpeon.com/synology-l2tpipsec-vpn/