Thursday, July 31, 2025

Daily IPv6 Connectivity Issue in Windows – How to Fix Permanently

 












🔍 Problem Summary:

  • Your Ethernet (wired) connection shows it's connected.

  • In ncpa.cpl > Properties > Details, it shows:

    • IPv4 connectivity: Internet

    • IPv6 connectivity: No Internet Access

  • After doing a Network Reset, it starts showing internet access on both IPv4 and IPv6.

  • But the problem returns daily — you have to reset every day.

🧠 What This Means:

This is a network stack or DNS issue, most likely due to:

Possible CauseExplanation
❌ Corrupted network stack or adapter settingsKeeps breaking IPv6 routing
🔁 Faulty DHCP lease or DNS configIPv6 not refreshing properly
🔌 Router/modem conflictMay not issue IPv6 address correctly
🔁 Power-saving settingsNIC may go to sleep and not recover full stack
🦠 3rd party security/firewall softwareMay interfere with IPv6 binding
📶 Driver issueNetwork adapter driver may misbehave after sleep/boot

✅ Step-by-Step Permanent Fixes

✅ 1. Disable & Re-enable IPv6 (Temporarily)

To confirm the problem is in IPv6 stack:

  1. Go to ncpa.cpl

  2. Right-click your Ethernet connection > Properties

  3. Uncheck Internet Protocol Version 6 (TCP/IPv6)

  4. Click OK

  5. Wait 30 sec

  6. Go back and re-check IPv6

Check if the issue resolves temporarily — this confirms the stack issue.

✅ 2. Set IPv6 DNS Manually

  1. Go to ncpa.cpl

  2. Right-click the Ethernet adapter > Properties

  3. Select Internet Protocol Version 6 (TCP/IPv6) > click Properties

  4. Select:

    • ✔️ Use the following DNS server addresses

    • Preferred: 2001:4860:4860::8888

    • Alternate: 2001:4860:4860::8844 (Google IPv6 DNS)

  5. Click OK

✅ 3. Reset TCP/IP and Winsock (Once)

  1. Open Command Prompt as Administrator

  2. Run these commands:

cmd
netsh int ip reset
netsh winsock reset
ipconfig /flushdns

Then restart your computer.

✅ 4. Turn Off Power Saving on Network Adapter

  1. Go to Device Manager

  2. Expand Network adapters

  3. Right-click your Ethernet adapter > Properties

  4. Go to Power Management

  5. Uncheck:

    • ❌ Allow the computer to turn off this device to save power

✅ 5. Update/Reinstall Network Driver

  1. Go to Device Manager > Network Adapters

  2. Right-click your Ethernet adapter > Update Driver

  3. Or choose Uninstall device (then restart – Windows reinstalls it)

You can also download the latest driver from your motherboard or laptop manufacturer website.

✅ 6. Check Router DHCPv6 Settings

Login to your router:

  • Go to DHCP settings

  • Make sure DHCPv6 or SLAAC is enabled

  • Some routers disable IPv6 by default

Also try rebooting the router.

✅ 7. Schedule a Daily Network Stack Reset (Workaround)

If it must be done daily, create a scheduled task to run on startup:

  1. Open Notepad, paste:

cmd
netsh winsock reset
netsh int ip reset

  1. Save as reset_network.bat

  2. Create a Task Scheduler job:

    • Trigger: At startup

    • Action: Run the .bat file as admin

🧩 Final Suggestion

If IPv6 is not essential in your network (most home setups use IPv4 mainly), you can disable IPv6 permanently:

  1. Go to ncpa.cpl

  2. Right-click your Ethernet > Properties

  3. Uncheck Internet Protocol Version 6 (TCP/IPv6)

This will not harm general internet access, unless you rely on specific IPv6-enabled services or servers.