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How to fix BT DNS issues using Google DNS

BT Building

Avoid downtime and speed up your browsing using Google DNS servers

Millions of people across the UK lose their internet access when BT’s DNS servers go down, which they often seem to do. DNS servers, otherwise known as Domain Name System servers, take easily remembered web addresses and translate them to the numerical IP addresses that computers understand, helping you get around the web easily. When the system goes down, your computer can no longer look up the address it’s supposed to be connecting to, making it look as though the entire internet is down. Thankfully  you can use the free Google DNS servers, which are much more stable than the ones used by many broadband suppliers. There are other free DNS servers you might want to use, instead. Read our guide on how to find a better DNS server.

To avoid unwanted DNS issues in the future, we’ve put together a complete guide on how to change your DNS servers, either through your home Wi-Fi router, on each device in the house, or through a NAS device.

Using static IP addresses

All wireless routers have built-in DHCP (Dynamic Host Configuration Protocol) servers. When a new device connects to them, they automatically dish out IP addresses and DNS server information. This is handy, as it saves a lot of time and effort, making networking easy. However, using this method, devices only lease an address; when the lease is up, they may end up using a new, different address. That’s no good for some devices, so to follow this article, you may need to configure some to use a static address, setting it manually. We’ll explain how, but before you do anything else you need to find out how to find out a safe address by connecting to your router.

Every router manufacturer does things slightly differently, but our directions should make sense regardless of which router you’re using. First off, open the configuration page: this is typically done by typing or into your web browser, but if you aren’t sure you can find out by typing “ipconfig” into a Windows command prompt, or “route -n” in a Mac Terminal Window. In both cases, the default gateway address is the IP address of your router, which you should enter into your browser’s address bar. Enter your username and password to login.

Look for the DHCP server settings. These will tell you the range of addresses the router gives out, which will include a start address and an end address. For the BT Home Hub 5, for example, it gives out addresses between and What you need to do, for devices that require it, is to use an IP address outside of this range; if you don’t, you may end up with two devices using the same address, which isn’t allowed and will cause problems.

To work out a safe IP address, you have to keep the first three numbers of range of addresses the same, such as 192.168.1, and then change the last number, so that it doesn’t clash with the router’s range. The only rules are that this number must be between 1 and 254, and don’t pick the same address that your router has. In the BT Home Hub 5 example, then, given the router has an IP address of and the range is quoted as above, anything between and is fine.

BT Home hub DHCP

Change DNS on Router

Most routers should let you alter the default DNS server addresses through their configuration page. This will affect every device that uses it to connect to the internet, making it the easiest way to change DNS servers if you have more than one internet-enabled device in the home. Unfortunately for BT Broadband customers, this isn’t possible on a BT Home Hub, meaning you’ll have to look further down the page for our on-device DNS settings guide. Connect to your router’s web-based management page and log in. Look for the section that contains your router’s internet (WAN) address, and you should be able to override the DNS server setting. Enter in the Google DNS server addresses, which are and

Netgear router DNS instructions

Once you’ve changed this setting, all of your devices will start to use the new DNS servers, so you won’t be affected next time BT (or any other ISP) has server problems.

Change on Device (BT Customers)

If you’re a BT Broadband customer, don’t have access to your router’s configuration page or your router doesn’t let you change the DNS servers, you can manually change DNS servers on each internet-connected device. It takes a little more time and effort, but by the end you’ll be able to get online without worrying whether your broadband provider’s DNS servers are up and running. At the least, it may be worth changing one device in your home, so that you can check if an internet error is due to a DNS problem or because your entire internet connection has gone down.


If you have a Windows laptop or desktop computer, you’ll need to open the Control Panel. Windows 8 users can hit the Windows key and type Control Panel, while older versions of Windows have a Control Panel shortcut in the Start Menu. From here, click Network and Sharing Center, then Change adapter settings on the left side of the window that opens. Next, right-click the connection you use to get online and select Properties. We’ve used Wi-Fi, but if you use a cable click Ethernet instead.

Microsoft Windows DNS settings

You should see a list under the heading ‘This connection uses the following items:’. Select Internet Protocol Version 4 (TCP/IPv4) and click Properties. In the new window that opens, change the radio button from ‘obtain DNS server address automatically’ to ‘Use the following DNS addresses’. Enter the Google DNS servers ( and and hit OK. Click Close on the previous window and you’re done.


If you’re using an iMac desktop or MacBook laptop, simply click on the System Preferences icon in the Dock then click on Network in the window that appears. Make sure the active network interface is selected (in our case it was Ethernet, but if you’re connected over wireless make sure to choose Wi-Fi) then click Advanced… in the bottom right corner of the window.

Mac OS X DNS settings

From here, select the DNS tab and hit the + icon at the bottom left of the window. Add the Google DNS server addresses ( and then hit OK to save your changes. Click Apply and you’re done.


For Apple mobile devices you need to be connected to your home Wi-Fi network. Go to Settings, Wi-Fi and then tap the ‘i’ next to the network you’re currently connect to. Go down to DNS and tap the field to edit the information that’s listed. Enter, ‘,’ (including the comma, excluding the quote marks). Tap Wi-Fi at the top of the settings page to go back and apply the settings.

iOS 7.1 DNS settings


For smartphones and tablets running Google’s mobile operating system, jump into the Settings menu and head for Wi-Fi. Make sure you’re connected to your local Wi-Fi network, then press and hold on its network ID to bring up a text box. Select the second option (Modify network config) and tick the ‘show advanced settings’ checkbox in the new window that appears. Now change the IP Settings dropdown box from ‘DHCP’ to ‘Static’. Enter a safe static IP address, as described at the start of this article.

Google Android DNS settings

You’ll then need to scroll down the page until you see two text boxes labelled DNS 1 and DNS 2. Put the two Google DNS server addresses ( and in these boxes and hit save to finish.

Change with DHCP on a NAS

If your router won’t let you change DNS addresses, but you don’t want the hassle of changing every single device on your network, you might be able to save some time using your NAS drive. Many models can take over from a router, handing out IP addresses to your connected devices and controlling, therefore, which DNS servers are used. We’ve used a Synology DiskStation in our example, but some other NAS devices have similar options. First off, open the NAS interface by typing its web address into your web browser, then logging in using your administrator or user account information. First, your NAS has to have a static IP address, so go to Control Panel, Network, Network Interface, click LAN and select Edit. Click IPv4 and select Use manual configuration, then enter a safe static IP address, as discovered at the start of this article. Enter the subnet mask as Click OK and you may have to reconnect to your NAS using the new IP address you gave it.

Once you’re back in the management console the instructions differ depending on the version of the Synology NAS you’re running. Only devices that have DSM 4.2 or higher installed (roughly 2009 and onwards) can run the DHCP server. For DSM 4.X devices, you have to install the DHCP server package using package manager, then you run it from the Menu; DSM 5.x devices shouldn’t need the package installing: the settings are in Control Panel, Network, Network interface, then click your LAN adaptor and click Edit, then click the DHCP server tap. Note, you can’t use the DHCP server if it has more than one network adaptor and it’s in Bridge mode. Both the DSM 4.X and 5.X versions have the same settings once you’re in them.

Select Enable DHCP server, then enter the Primary DNS as and the Secondary DNS as Click the Add button, then under Start IP address enter the same start address as used by your router (see the top of this article for more information), and the end IP address as your router’s end address. Enter the Netmask as and the Gateway as your router’s IP address. Click the Enabled tick box and click OK.

Synology NAS DHCP server

Now, connect to your router’s web-based management page and find the DHCP server settings (for the Home Hub they’re in Advanced Settings, IP Addresses) and disable the DHCP server. Apply your settings and all new devices that connect to your network will have new DNS and IP address settings as dished out by your NAS. Devices currently on the network may have to be rebooted or have their power cycled to pick up their new addresses.