Four Common Problems with your VPN Connections

A few years ago, the usage of Virtual Private Network (VPN) connection was not that common. People rarely used virtual private connections. With the passage of time, people got aware of how important it can be. People didn’t even know what is a VPN connection then? Things have changed. Things have changed for better. Nowadays you can see majority of people protecting their internet connection with a VPN. VPNs are not only used for privacy and security but also to help you access those geo-restricted websites that you otherwise couldn’t have. Though VPNs usually function pretty smoothly and are reliable, people do experience a few problems. Out of these common VPN connection problems experienced by VPN users, here are the four of the commonest ones and their solutions.

1 – VPN Connection attempt rejected:

• This is a very common problem among VPN users. It can occur due to a number of reasons. To check out the reasons why this problem is occurring, start with checking if the Route and Remote Service is functional. This can be viewed on the server’s control panel under the Services tab. If it is working, then try the pinging technique to ensure that TCP/IP connectivity is active. If you are not aware about the pinging technique, here is a quick rundown:

You ping the server by IP address of the client. If it successfully pings, try another ping but with server’s fully qualified domain name (FQDN). If the ping does not go through, you’d know the problem exists with your DNS.

• Check that the VPN server and the VPN client must have at least one common authentication method.
• You should also check out the path connection, via which client is trying to reach the server. If it’s dialing in to the server instead of establishing a connection via internet, it may be the case that user does not have the dial-in privileges.
• While setting up the server, mention if the server will assign IP addresses via DHCP server or you will provide the IP addresses to give to each client. In case the server runs short of provided IP addresses, the VPN connection attempt will be rejected.

2 – Unauthorized Connection attempt accepted.

This is a rare problem but a serious one due to privacy and security concerns. If you encounter this problem with your VPN connection:

• Ensure that the specification does not allow permission through remote access.
• Check the Active Directory Users and check if the dial-in tab shows the option to control the access. In case the remote access is allowed, user can connect to the VPN.
• Rumor is that there is a bug in Windows 2000 that allows the VPN connection even if the remote access policy is configured to reject it.

3 – Not being able to reach locations beyond the VPN server.

This is also a common problem that hinders a user’s access to the network beyond the VPN connection server. This occurs when the user is not permitted to access the entire network. To remedy this, follow the following steps:

• Access the Routing and Remote Console and open the properties of the VPN server in question. Check if the option, “Enable IP Routing”, in IP tab is checked. All VPN and RAS users would get access to the network. If the box is unchecked, the users will only be able to access the VPN connection and nothing above that.
• In the event of you utilizing a DHCP server to allot IP addresses that are already in use, it will be identified and the said user will be restricted from accessing the network.

4 – Not being able to create a tunnel.

If you are experiencing problems while establishing a tunnel between the client and the server, there could be two things preventing the connection. First could be that the routers involved in the operation are performing IP packet filtering. If so, double check the client, server and the machines i.e. routers for IP Packet filters.

It could also be due to a proxy server coming in between the client and the server. The packets travel from the proxy instead of the client. The said interaction also disrupts the establishment of a tunnel in a few cases.

This brings us to the end of this post. Feel free to contribute to this blog with your suggestions in the ‘comments’ section below. Your contribution will be highly appreciated.