1. A 721 error occurred while dialing the VPN Client.
This case is often because of the customer system. If it is WINXP and SP2 is installed, this situation may occur. The solution is to modify the registry: HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control \ Class \ {4D36E972-E325-11CE-BFC1-08002bE10318 }\< 000x>
<000x> is the network adapter of the WAN micro port (PPTP) driver. In this case, create a DWORD Value ValidateAddress and set it to 0.
This type of error is also caused by incorrect server-side PPP protocol configuration.
2. A 800 error occurred while dialing the VPN Client.
This is often because the customer's system uses the domain name when connecting to the server. This error occurs because the temporary DNS cannot be resolved. You can change the DNS and try again. If the problem persists, it may be unable to connect to the VPN Server. It may be because the VPN Server is closed or fails, or the firewall on the customer's computer blocks the VPN connection request. You can close the firewall and try again.
Some clients that use the Transit server to connect to the VPN Server may also encounter such errors because the transit function of the Transit server fails.
3. A 619 error occurred while dialing the VPN Client.
This is often because the client connects to the Internet gateway (such as home broadband routing or corporate Internet gateway routing or firewall) NAT-T function is disabled or VPN support is not good, the NAT-T for GRE and PPTP protocols is not supported. You can turn on the NAT-T feature of gateway routing, if there is still an error, You need to replace the gateway device, most of the devices on the market now support.
4. A 691 error occurred while dialing the VPN Client.
This is often because the client connects to the VPN Server abnormally and is interrupted. Because most servers limit one account and only one account is used at the same time, it takes about 3 minutes to disconnect an exception. Some VPN servers do not have the exception disconnection check function, which may cause users to be unable to connect for a long time after they are disconnected. Therefore, the solution is to set the exception disconnection check program or function on the server.
5. A 733 error occurred while dialing the VPN Client.
In this case, the IP address cannot be obtained after the client dials the VPN Server. You can fix the DHCP server or set a static IP address or address pool.
6. When the VPN Client is dial in, the 734 ppp Connection Control Protocol is terminated.
In this case, most VPN Server configurations are incorrect. If the PPP configuration is incorrect, MPPE encryption or poor support is not supported. Recompile the PPP and MPPE programs. Users used for game proxies do not use encryption (encryption is not required on the server side ).
7. A 718 error occurred during VPN Client Access.
The user name and password are incorrect during the dial, and sometimes the server authentication service fails.