VPN Pass-Through Setup | DrayTek
How can I open PPTP traffic to a PPTP server behind the The Point-to-Point Tunneling Protocol (PPTP) is a method for implementing virtual private networks. PPTP uses a control channel over TCP and a GRE tunnel operating to encapsulate PPP packets. A PPTP tunnel is instantiated by communication to the peer on TCP port 1723. This TCP connection is then used to initiate and manage a second GRE tunnel Set up VPN Server - Synology DSM Help Please check the port forwarding and firewall settings on your Synology NAS and router to make sure the TCP port 1723 is open. PPTP VPN service is built-in on some routers, the port 1723 might be occupied. To ensure VPN Server works properly, you might need to disable the built-in PPTP VPN service through the router's management interface to Open ports to VPN server | Netgate Forum
How to Enable VPN Passthrough - IPsec Firewall Port - Tom
Some networks block the basic requirements for PPTP VPN connections. Hotels sometimes do this prevent guests from skirting their internet content policies. To establish a PPTP VPN connection, the host network must allow traffic on port 1723 and Generic Route Encapsulation (GRE) 47 traffic.
Ports used for VPN Protocols – IPVanish
Jul 23, 2020