The PPP link control protocol was aborted, error 734.

Some PC users may not be able to create a dial-up connection because whenever they try to establish a Point-to-Point Protocol (PPP) dial-up connection using their VPN on a Windows 11 or Windows 10 PC, they get the message The The PPP link control protocol has been discontinued. Error code 734 is related to this issue and is more related to the dial-up connection than the VPN error. This post provides the most appropriate solutions to the error.

Can’t connect to *VPN/Dial-up Connection Name*
The PPP link control protocol was terminated.

What is PPP Link Control Protocol?

The PPP Link Control Protocol (LCP) establishes a PPP link by negotiating with a PPP peer at the other end of the intended connection. When two routers initiate a PPP conversation, each router sends control packets to the peer. A PPP error can occur in some cases if the username or password is incorrect with an error message Failed to authenticate yourself to the peer-to-peer network. In this case, you need to verify the username and password with your ISP.

You may encounter this error for one or more of the following reasons;

• Invalid dial-up connection because multi-link negotiation is enabled for a single-link connection.
• The remote access security configuration is incorrectly configured to use the Require secure password option.
• Incorrect network connection settings.
• The Microsoft CHAP version is disabled.
• Data encryption is set to optional.
• Firewall interference.

The PPP link control protocol was aborted, error 734.

If you encounter the PPP Link Control Protocol was interrupted message when trying to establish a PPP dial-up connection using a VPN on your Windows 11/10 PC, you can try our recommended fixes below in no particular order and see if it helps you resolve the issue in your system.

1. Configure PPP settings for a dial-up connection
2. Change dial-up connection configuration
3. Temporarily disable firewall

Let us consider in detail the description of these listed solutions.

1]Configure the PPP settings for the dial-up connection.

You are likely to experience the error PPP Link Control Protocol terminated on your Windows 11/10 PC due to your dial-up protocol settings. So, to start troubleshooting, you can make sure that the dial-up PPP settings are correctly configured on your device; and to do this, you need to make sure that a hidden protocol called Microsoft CHAP (Challenge Handshake Authentication Protocol) version 2 (MS-CHAP v2) is enabled – a password-based authentication protocol that is widely used as an authentication method based on PPTP (Point Point Tunneling Protocol). ) VPN.

To configure PPP settings for a dial-up connection, follow these steps:

• Press Windows + R to bring up the Run dialog box.
• In Run type ncpa.cpl and click Enter open Network Connections let.
• In the window that opens, right-click on dial-up network connection.
• Choose Properties .
• On the property page, click security.
• Scroll down and click radio to Allow these protocols.
• Now clear all checkboxes except Microsoft CHAP version 2 (MS-CHAP v2).
• Then, in the VPN Type section, click the dropdown and select point to Point Tunneling Protocol (PPTP).
• Click OK to exit and save changes.

See if the issue is resolved. Otherwise, try the next solution.

2]Change dial-up connection configuration

The highlighted error may occur due to conflicting or incorrect network configurations or connection security settings configured to require a secure password. This solution requires that you make changes to the dial-up connection configuration by disabling the multilink option for a single link connection. To complete this task, follow these steps:

• Press Windows + R to bring up the Run dialog box.
• In Run type ncpa.cpl and press Enter to open Network Connections let.
• In the window that opens, right-click on dial-up network connection.
• Choose Properties .
• Click options.
• Click PPP Settings.
• Now click to clear (if selected) Negotiate multi-link connections for single-link connections.
• Click OK > OK.
• double click connection.
• Click Dial .

If you can now successfully establish a dial-up connection, then that’s good. Otherwise, follow these steps to change connection security settings:

• Right click dial-up connection over network connections.
• Choose Properties .
• Click security .
• Under Security Options, click allow insecure password in Validate my personality is as follows.
• Click OK.
• double click connections, and then click Dial to make sure you can establish a dial-up connection.

3]Temporarily disable the firewall

It is known that sometimes you can experience issues with VPN or dial-up connection due to the interference of security software such as Windows Firewall and especially third party firewalls. So, to eliminate this possibility, you can disable the firewall. If you have installed third party custom firewall software or antivirus software that integrates the firewall, you can check the settings page or refer to the product manual for instructions.

To disable Windows Firewall on your device, follow these steps:

• Press Windows + R to open Run.
• In Run, type ms-settings:windowsdefender and click Enter open Windows Security Center.
• Under Windows Security, click Firewall and Network Protection in the right pane.
• Next select currently active network in the Firewall and network protection menu.
• Now disable the Microsoft Defender Firewall button.
• Exit the Windows Security Center.

What LCP features were used in PPP?

LCP (Link Control Protocol) is used to control a PPP link by sending special LCP messages over the physical link between the sending and receiving devices; messages are called LCP packets or frames. Each LCP frame is encapsulated in the payload field of a PPP frame. Each frame corresponds to the life phase of a PPP link.

How to fix PPPoE connection?

To fix PPPoE connection issue for SonicOS 7.X, you can try the following suggestions:

• Ensure correct power connection.
• Check the WAN link indicator.
• Try restarting your DSL modem and SonicWall.
• Make sure there are no problems with the DSL modem or line (PPPoE discovery is not complete).
• Make sure the username and password are correct (successful or unsuccessful authentication).

What does error 651 mean when connecting to the internet?

If you are getting error 651 when connecting to the Internet, this indicates that the connection between your PC and the DSL router or DLAN adapter has been interrupted. If you receive error 691, this means that the remote connection was refused because the username/password combination you entered was not recognized, or the authentication protocol you selected is not allowed on the remote access server. In addition, the number of incorrect domain user passwords may increase, resulting in an account lockout.

Is PPP still in use?

PPP (Point-to-Point Protocol) is a wide area network protocol that is often used in point-to-point links. Initially, PPP was often used for dial-up connections. It is currently still used for DSL with PPPoE (PPP over Ethernet) and PPPoA (PPP over ATM). PPP has stronger security such as password encryption and IP address verification. This reduces the chance that an attacker can establish a network connection.