Summary of common VPN error codes

Virtual private networks (VPNs) create protected connections called 'VPN tunnels' between a local client and a remote server, usually over the Internet. VPN can be difficult to set up and run only with relevant specialized technology.

When the VPN connection fails, the client-side program will appear an error message containing some code. There are hundreds of different VPN error codes that exist but only certain codes appear in most cases.

Many VPN errors only require basic network troubleshooting steps to resolve:

1. Make sure the computer running VPN is connected to the Internet and access to the external network is active.
2. Make sure the VPN client has the correct network settings needed to work with the VPN server.

Temporarily turn off the firewall, local network to determine if it interferes with the VPN connection. Some types of VPNs require a certain number of network ports.

Here are some more specific ways to overcome:

VPN 800 error

"Unable to establish connection" - The VPN client cannot connect to the server. This can happen if the VPN server is not properly connected to the network, the network temporarily stops working or if the server or network is overloaded because the traffic is too large. VPN 800 error also occurs if the VPN client has incorrect configuration settings. Finally, the local router may not be compatible with the type of VPN being used and need to update the router firmware.

VPN 619 error

"A connection to the remote computer could not be established" - A VPN 619 error occurs when a firewall or port configuration issue is preventing the VPN client from making a connection even though the server is accessible.

Error 51 VPN

"Unable to communicate with the VPN subsystem" - Cisco VPN client reports this error when the local service is not running or the client is not connected to the network. Restart VPN service and / or troubleshoot local area network connectivity.

VPN 412 error

"The remote peer is no longer responding" - Cisco VPN client reports this error when the active VPN connection is stopped due to a network error or when the firewall interferes with access to the required ports.

VPN 721 error

"The remote computer did not respond" - A Microsoft VPN reported this error when unable to establish a connection, similar to the 412 error reported by Cisco clients.

VPN 720 error

"No PPP control protocols configured" - On Windows VPN, this error occurs when the client lacks protocol support to connect to the server. Fixing this problem requires determining which VPN protocol the server can support and installing an appropriate protocol on the client through the Windows Control Panel.

Error 691

"Access denied due to username and / or password là không hợp lệ trên miền" - User may have entered the wrong name or password when trying to authenticate with Windows VPN. For Windows computers, the login domain must also be specified correctly.

VPN error 812, 732 and 734

"The connection was prevented by a policy configured on your RAS / VPN server" - On Windows VPN, the user trying to authenticate the connection may not have access. The network administrator must resolve this issue by updating the user rights. In some cases, administrators may need to update support for MS-CHAP (authentication protocol) on the VPN server. Any of the three error codes can apply this fix depending on the network infrastructure involved.

VPN 806 error

"Một kết nối giữa máy tính của bạn và máy phục vụ VPN đã được thực hiện nhưng kết nối VPN không thể được thực hiện." - This error indicates that the router firewall is blocking some VPN protocol traffic between client and server. Typically, it is TCP port 1723 and must be open by the network administrator.

See more:

1. 10 common mistakes of VPN and how to fix it
2. How to use VPN Gate fake IP to stabilize the Internet
3. Speed ​​up Internet connection by VPN virtual private network solution