Event Viewer RAS Error 720 connecting to a L2TP VPN (Windows)

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mMontana
mMontana Posts: 1,338  Guru Member
First Anniversary 10 Comments Friend Collector First Answer
edited January 2023 in Security
Today I encountered this kind of problem: a (new) user was not able to connect via L2TP to the corporate network.
User followed correct instruction and everything worked as intended.
I tested credentials kit in another computer and worked like a charm; however, the laptop was not cooperating with the connection, even after triple check of the info.

Accepted Solution

  • mMontana
    mMontana Posts: 1,338  Guru Member
    First Anniversary 10 Comments Friend Collector First Answer
    Answer ✓
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    These steps have been taken for solving the issue:
    • Verified every parameter of the VPN connection (LCP extensions, MS-CHAP v2 enabled, disabled IPv6 and Windows client on the connection, Pre-shared key)
    • Diagnosed the status of the system via shell command "sfc /scannow" (no error present)
    • Verified this article for troubleshooting Error 720 on Windows
    According to the problem I managed, the issue was related with WAN Miniport (IP) driver/network card. I solved applied "Scenario 3", removing "WAN Miniport (IP)" card on the PC and requested "Scan for hardware changes". This operation reinstalled the virtual network card and solved without reboot my problem.
    However: your mileage may vary (AKA: does not mean that removing the "WAN Miniport (IP)" is the correct solution for you), so take care to fallow all steps for diagnose that Microsoft propose.



All Replies

  • mMontana
    mMontana Posts: 1,338  Guru Member
    First Anniversary 10 Comments Friend Collector First Answer
    Answer ✓
    Options
    These steps have been taken for solving the issue:
    • Verified every parameter of the VPN connection (LCP extensions, MS-CHAP v2 enabled, disabled IPv6 and Windows client on the connection, Pre-shared key)
    • Diagnosed the status of the system via shell command "sfc /scannow" (no error present)
    • Verified this article for troubleshooting Error 720 on Windows
    According to the problem I managed, the issue was related with WAN Miniport (IP) driver/network card. I solved applied "Scenario 3", removing "WAN Miniport (IP)" card on the PC and requested "Scan for hardware changes". This operation reinstalled the virtual network card and solved without reboot my problem.
    However: your mileage may vary (AKA: does not mean that removing the "WAN Miniport (IP)" is the correct solution for you), so take care to fallow all steps for diagnose that Microsoft propose.



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