Network · medium

How to fixIPV6-LEAK-TUNNEL

IPv6 tunnel causes connectivity issues

What this error means

IPv6 tunnel causes connectivity issues is a medium-severity network adapter issue. Windows automatically creates a 6to4 or Teredo tunnel for IPv6, which causes the connection to slow down or fail. Work through the steps below in order.

Before you begin

Save open work and back up important files. Note any recent driver or hardware changes. If Windows cannot start, use the startup guide first.

Work through these checks

0 of 3 complete
01Disable IPv6 via network adapter interface

Disable IPv6 via network adapter interface.

Use the instructions for your exact device and operating system. Check the manufacturer’s documentation before changing firmware, hardware, or system settings.

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02Disable Teredo tunneling: netsh interface teredo set state disabled

Disable Teredo tunneling: netsh interface teredo set state disabled.

Use the instructions for your exact device and operating system. Check the manufacturer’s documentation before changing firmware, hardware, or system settings.

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03Try disabling IPv6 globally via the registry

Try disabling IPv6 globally via the registry.

Use the instructions for your exact device and operating system. Check the manufacturer’s documentation before changing firmware, hardware, or system settings.

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Possible causes

  • ISP does not support IPv6, but Windows automatically activates it
  • Conflict between VPN and IPv6 address