Therefore, you may have to disable the IPv6 option to prevent the IPv6 leak. To do this, open Synology DSM's Control Panel. There: 1 click Network → Network Interface. 2 Highlight the LAN interface and click Edit at the top. 3 Switch to the IPv6 tab and for IPv6 setup, select Off.

Specifies the state of Teredo. The acceptable values for this parameter are: Disabled: Disables the Teredo service. Client. Enables the Teredo client. Enterpriseclient. Skips the managed network detection. Server. Enables the Teredo server. Relay. Automatic. Default. The default state is client. It is common for IT administrators to want to disable IPv6. This is often because of some unknown, networking-related issue, such as a name resolution issue. Important Internet Protocol version 6 (IPv6) is a mandatory part of Windows Vista and Windows Server 2008 and newer versions. We do not recommend that you disable IPv6 or its components. Teredo is installed but disabled. I've followed countless guides disabling/re-enabling to reinstall it but never ts further than being disabled. I've checked the registry entries and it's not disabled there. I also don't see it in the legacy hardware list : Press Windows key + R on your keyboard and type the following command in the command prompt and hit enter, netsh interface Teredo set the state to disable. Now, from the Start menu and look for Device Manager. In the Device Manager window, click on View>Show Hidden Devices and then double-click on Network Adapters to expand all the items. netsh interface Teredo set state disable; Once the interface has been disabled, close the elevated Command Prompt and reboot your computer. At the next startup, open another elevated Command Prompt window (using step 1), type the following command and press Enter: netsh interface Teredo set state type=default

To disable unused IPv6 transition protocols on a per-host basis on Windows 7 client using netsh, open an elevated command prompt and execute the following commands: netsh interface 6to4 set state disabled netsh interface teredo set state disabled netsh interface isatap set state disabled

Even if you disable IPv6, you can't disable IPv6 on pfSense itself. These days, IPv6 is the main network protocol - and IPv4 is the "tolerated while time lasts" protocol. So, your DNS - the Resolver - will still resolve any URL to AAAA and A if they exist. Teredo is a networking protocol that used to establish secure connections between client and servers. If the Teredo interface is not working or cannot be enabled, means that something is blocking Teredo from starting (e.g. you Firewall program), or that the Teredo interface is not properly installed and enabled on the system. The reason you disable tunneling is that some of the malware encountered, makes use of this and tunnels to IPv4 to get out. Once you have run both commands then you need to reboot the server. You will notice now on the adapter settings in control panel the tick is gone next to IPv6.

Set Teredo State - Enable - choose "Client" (If after doing all steps it fails, try choose Enterprise Client instead.) After that, Win+R , services.msc, look for "IP Helper" and restart services. Now , Win+R, cmd, input " netsh interface teredo show state" and you should be seeing something like this:

At command prompt, to disable IPv6 from all interfaces, type these commands. Then press enter - one command at a time. netsh interface teredo set state disabled netsh interface ipv6 6to4 set state state=disabled undoonstop=disabled netsh interface ipv6 isatap set state state=disabled How to Disable TCP/IPv6 Teredo Tunneling in Windows. Tags aix apple backup centos chef cloud dell ESXi google hardware hyper-v intel iOS iphone licensing linux Linux VM Performance Tuning microsoft pseuro-interface oracle linux performance Perl Puppet red hat red hat enterprise linux security solaris solarwinds ssd ssh SSL storage sysadmin tuneling field day tuning vCenter vCSA veeam Specifies the state of Teredo. The acceptable values for this parameter are: Disabled: Disables the Teredo service. Client. Enables the Teredo client. Enterpriseclient. Skips the managed network detection. Server. Enables the Teredo server. Relay. Automatic. Default. The default state is client. It is common for IT administrators to want to disable IPv6. This is often because of some unknown, networking-related issue, such as a name resolution issue. Important Internet Protocol version 6 (IPv6) is a mandatory part of Windows Vista and Windows Server 2008 and newer versions. We do not recommend that you disable IPv6 or its components.