Hi all,
I'm having trouble establishing a PPTP VPN connection to my Mikrotik Router (CCR2004-1G-12S+2XS). From Windows, the error I am receiving is "The VPN connection between your computer and the VPN server could not be completed ... the VPN server is not configured to allow Generic Routing Encapsulation (GRE) protocol packet..."
The issue does not occur for all clients connecting to the VPN. Some with users coming from different ISPs can connect, others cannot & receive the message above. So I am thinking the cause could be with some ISPs.
How do I ensure that the config is set properly on the router?
Under Firewall -> Filter Rules both Protocols GRE & TCP are configured to accept connections (Input Chain) as well as the PPTP service port enabled on port 1723. Oddly enough, users were still able to connect to the VPN before any of these three config changes were done.
Am I missing any steps?