Setup Router logo in white Setup router name logo in white
Get Software

How to Reset the Dasan H640DW Viettel

Thumbnail image of Setup Router Staff
Setup Router Staff
(Last Updated: ) | Reading Time: 3 minutes

On this page I will show you how to reset the Dasan H640DW Viettel router back to factory default settings. It's important that you know this is not the same thing as a reboot. When you reboot a router you cycle the power to the device in order to solve some minor problems you may be having with the device. When you reset a router you take all the settings and revert them all to how they were from the factory.

Warning: Resetting a router can be a problem if you don't understand what setting will be changed. Please consider the following:

  • The router's main username and password are reverted to factory defaults.
  • The Internet information is also reverted to factory defaults. This includes the SSID or network name and the Internet password.
  • If you use a DSL router you need to re-enter the ISP username and password. This information can be found by calling your local Internet Service Provider.
  • All other settings are returned to factory defaults as well. This includes anything you have ever changed on this device.

Other Dasan H640DW Viettel Guides

This is the reset router guide for the Dasan H640DW Viettel. We also have the following guides for the same router:

Reset the Dasan H640DW Viettel

Use a VPN Instead

Have you considered using a VPN instead of forwarding a port? For most users, a VPN is a much simpler and more secure choice than forwarding a port.

We use and recommend NordVPN because not only is it the fastest VPN, it includes a new feature called Meshnet that makes forwarding a port no longer necessary for most applications. With NordVPN Meshnet, you can connect to your devices from anywhere in the world, completely secure, over a highly encrypted VPN tunnel.

When shopping for a VPN, make sure that they meet the following criteria:

  • Your VPN provider should have a no-logs policy. This means that they do not keep any logs of any kind.
  • Make sure that your VPN provider has lots of exit nodes all around the world.
  • Check that your VPN will not affect your speed.
  • Verify that your VPN provider uses WireGuard as the underlying protocol.
  • Many people prefer a VPN provider that is not based in the United States.

This is the list of requirements that we used when we were shopping around for a VPN provider. There are lots of free, shady VPN providers out there that we looked at and dismissed.

Based in Panama, using diskless servers, and with over 6,100 servers in 61 countries, we can safely say that NordVPN satisfies all of these requirements.

NordVPN faster than ever deal!

Once you've set up your NordVPN account on multiple computers and enabled Meshnet, you can seamlessly access all of your devices as if they were on the same network. You don't even have to log in to your router. It's very simple.

Every time you click on one of our affiliate links, such as NordVPN, we get a little kickback for introducing you to the service. Think of us as your VPN wingman.

The first step to resetting this router is locating the reset button. Unfortunately we are unable to find an image of the reset button for this device. We can show you a typical location however just look at the reset button in the image below.

router reset factory settings
This is the reset page from your Dasan H640DW Viettel router.

As you can see this button is usually on the back panel. If it is not there take a look all over the outside of the router, it could be anywhere. Take the tip of an unfolded paperclip and press down on the reset button for about 10 seconds to initiate the reset process. If you don't hold this button down for long enough you end up only rebooting the router instead of the reset you were trying to do.

Remember this reset is erasing every setting you have ever changed on your device. If you want to avoid losing all your settings you should definitely try other troubleshooting methods first.

Login to the Dasan H640DW Viettel

After resetting your Dasan H640DW Viettel router you'll need to log into it. Use the default username and password to do this. Don't have these? Not to worry. We have them for you in our Login Guide.

Tip: If the defaults don't seem to be working for you it may be because the reset button wasn't held down for long enough.

Change Your Password

Now that you've logged in you should change the default password. This can be anything you want, however we recommend using the tips in our Choosing a Strong Password Guide.

Tip: Avoid losing your password by writing it on a sticky note and putting it on the underside of your router.

Setup WiFi on the Dasan H640DW Viettel

Now is a good time to configure your wireless settings as well. Make sure you are using the proper security for your network. We recommend using WPA2 with a strong Internet password. Learn more about how to do this on our page titled How to Setup WiFi on the Dasan H640DW Viettel.

Don't forget to sign up for NordVPN's promo deal before it's gone.

NordVPN birthday deal!

You might notice that most of our site doesn't have ads on it. This is because we use partnerships with companies like NordVPN to keep the site running. Thank you for supporting us by using our referral links.

Dasan H640DW Viettel Help

Be sure to check out our other Dasan H640DW Viettel info that you might be interested in.

This is the reset router guide for the Dasan H640DW Viettel. We also have the following guides for the same router: