Client Fails to connect the PPTP Server
PPTP is a tunneling protocol that encapsulates the data packet in an envelope. The main thing that is important to remember is that the PPTP works around a RAS server. The advantage of the encapsulation by the PPTP is that it gives the flexibility to roué several different protocols across IP. PPTP was designed to connect users to the RAS server from any point over the internet and provide the capabilities of authentication and encryption. In VPN both the PPTP and RAS use the authentication and encryption techniques to set up a virtual private network (VPN).In this article, we would discuss the root causes and will find a solution to ‘client fails connecting PPTP server’
This is also a major issue that is faced by WordPress users while working out on the VPN connections server. If you will have your VPN connections not working fine, then there can be three possible causes for this problem and we can try the following ways to get rid of this error.
Error while establishing VPN Server connectivity
- Check if the VPN server had proper connectivity with the internet or not. You can do that by simply making a ping request to the server IP address. Open the CMD console and type in the command Ping server IP-address.
- If the server is behind a firewall, nothing would happen but if there is an issue with the internet connectivity of the server, a message ‘request time out’ would be displayed.
- Now, If the server makes a reply from its address then you should enter the server address in the phone number field of the DUN entry to connect to the server via a PPTP session.
- Note that in case of a dial-up connection you must have knowledge of the IP address of the server assigned by the Internet service provider.
Check the PPTP filtering
If the PPTP filtering is enabled on the server, then an error message ‘Error 678: There is no answer’ or ‘Error 650: The Remote Access Server is not responding’ would get appeared.
Simply disable the PPTP filtering and watch out for the connection to the VPN server has been established or not.
If you get successfully connected to the VPN server then simply check for the filter settings for the server. Enable the UDP ports 137, 138, and TCP port 139 on all the firewalls and routers that exist between the client and the server. This is essential for unicast traffic.
Filter the GRE Protocol
Now if your server is responding and replying to your ICMP requests but still you are not able to connect to the server, then it means that your Routers and firewall are filtering the GRE packets. And the exchange of the GRE packets is important to establish a successful PPTP session. But sometimes the internet service providers disable the GRE packets. To deal up with this situation you must keep the IP protocol 47 and TCP port 1723 enabled on both ends of the connection. You can use any network sniffing tool to identify GRE filtering.
Conclusion
In this article, we have tried to troubleshoot the major issue ‘client cannot connect to the PPTP server’ which causes problems in accessing the services while using a VPN connection. You can implement the above ways to get rid of this problem and can enjoy your VPN services.