Solved: How to allow PPTP VPN Access through AS - Cisco
For Windows, you may try in regedit to search for TcpPortNumber and change its value from 1723 to the new port number, then reboot. In my computer this is found in : HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\ {4D36E972-E325-11CE-BFC1-08002BE10318}\0001 Change port number VPN Connection PPTP May 09, 2011 How to set up VPN server with port forwarding? | Official Apr 24, 2019 How to change PPTP VPN client's port number? - Android
As you can see it is defined in pptpdefs.h - and as such in order to change this port - you would have to recompile. It may be possible on the server side to preform an IPTables src-nat to accept connections on another port and redirect this - however I would suspect that the client would still need to be updated.
May 16, 2013 macos - How to define the VPN PPTP port in OSX Lion? - Ask
Jan 24, 2020
Which ports do you need to open on a firewall to allow To enable VPN tunnels between individual host computers or entire networks that have a firewall between them, you must open the following ports: PPTP. To allow PPTP tunnel maintenance traffic, open TCP 1723. To allow PPTP tunneled data to pass through router, open Protocol ID 47. L2TP over IPSec. To allow Internet Key Exchange (IKE), open UDP 500. MikroTik CHR: How to set-up PPTP VPN Server A quick guide to configure Mikrotik CHR as PPTP VPN Server.For L2TP VPN Server - check the end of this article! Both Command Line Interface Point-to-Point Tunneling Protocol - Wikipedia 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 GRE tunnel to the same peer. The PPTP GRE packet format is non standard, including a new acknowledgement number field replacing the typical routing field in the GRE header. However, as in a normal GRE connection, those modified GRE packets are directly … PPTP Server Configuration - DD-WRT Wiki