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Blocking Ads using the Ad Blocking DNS Server
Using Ad Blocking DNS Server is one of the best ways to prevent Ads. The benefits of using this method are that you get improved security, privacy, and blocking the annoying Ads. There are some perfect Ad Blocking DNS servers such as AdGuard and Alternative DNS. You can use any of these services, but we are using the Alternative DNS here. Here’s how you can do it.

Open the Settings
Find “My Fire TV” and open it.
In this section, go to about section and tap “Network.” We will use it later.
Now go to settings again, go to Network section, and select your Wifi. Tap the “Forget this network.” Use this step if your Firestick is connected to your Wifi.
Now go to connections and tap the Advanced.
Enter the IP Address, Gateway, and Subnet Mask from the picture you took in the first step.
Now Enter the Primary (DNS1) and Secondary (DNS2) settings and tap “next.”
In this way, you can easily set up the Ad Blocking DNS on your Firestick and get rid of the Ads.

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Free and Public DNS Servers
Updated list of the best publicly available and free DNS servers
The best free public DNS servers include Google, Quad9, OpenDNS, Cloudflare, CleanBrowsing, Verisign, Alternate DNS, and AdGuard DNS.

Here's a quick reference if you know what you're doing, but we get into these services a lot more later in this article:

Best Free & Public DNS Servers
Provider Primary DNS Secondary DNS
Google 8.8.8.8 8.8.4.4
Quad9 9.9.9.9 149.112.112.112
OpenDNS Home 208.67.222.222 208.67.220.220
Cloudflare 1.1.1.1 1.0.0.1
CleanBrowsing 185.228.168.9 185.228.169.9
Verisign 64.6.64.6 64.6.65.6
Alternate DNS 198.101.242.72 23.253.163.53
AdGuard DNS 94.140.14.14 94.140.15.15
(A comprehensive list of additional free DNS servers can be found in the table near the bottom of the page)

What Are DNS Servers?
DNS servers translate the friendly domain name you enter into a browser (like lifewire.com) into the public IP address that's needed for your device to actually communicate with that site.

Your ISP automatically assigns DNS servers when your smartphone or router connects to the internet but you don't have to use those. There are lots of reasons you might want to try alternative ones (we get into many of them in Why Use Different DNS Servers? a bit further down the page) but privacy and speed are two big wins you could see from switching.

Primary DNS servers are sometimes called preferred DNS servers and secondary DNS servers sometimes alternate DNS servers. Primary and secondary DNS servers can be "mixed and matched" from different providers to protect you if the primary provider has problems.

Best Free & Public DNS Servers (Valid November 2020)
Below are more details on the best free DNS servers you can use instead of the ones assigned.

If you're not sure, use the IPv4 DNS servers listed for a provider. These are the IP addresses that include periods. IPv6 IP addresses use colons.

GOOGLE: 8.8.8.8 & 8.8.4.4
Google Public DNS website
Google Public DNS promises three core benefits: a faster browsing experience, improved security, and accurate results without redirects.
Primary DNS: 8.8.8.8
Secondary DNS: 8.8.4.4

Google also offers IPv6 versions:
Primary DNS: 2001:4860:4860::8888
Secondary DNS: 2001:4860:4860::8844

Google can achieve fast speeds with its public DNS servers because they're hosted in data centers all around the world, meaning that when you attempt to access a web page using the IP addresses above, you're directed to a server that's nearest to you.

QUAD9: 9.9.9.9 & 149.112.112.112
Quad9 has free public DNS servers that protect your computer and other devices from cyber threats by immediately and automatically blocking access to unsafe websites, without storing your personal data.

Primary DNS: 9.9.9.9
Secondary DNS: 149.112.112.112

There are also Quad 9 IPv6 DNS servers:
Primary DNS: 2620:fe::fe
Secondary DNS: 2620:fe::9
Quad9 does not filter content—only domains that are phishing or contain malware will be blocked. Quad9 also has an unsecured IPv4 public DNS at 9.9.9.10 (2620:fe::10 for IPv6).

OPENDNS: 208.67.222.222 & 208.67.220.220
OpenDNS claims 100% reliability and up-time and is used by 90 million users around the world. The offer two sets of free public DNS servers, one of which is just for parental controls with dozens of filtering options.

Primary DNS: 208.67.222.222
Secondary DNS: 208.67.220.220

IPv6 addresses are also available:
Primary DNS: 2620:119:35::35
Secondary DNS: 2620:119:53::53

The servers above are for OpenDNS Home, which you can make a user account for to set up custom settings. The company also offers DNS servers that block adult content, called OpenDNS FamilyShield: 208.67.222.123 and 208.67.220.123 (shown here). A premium DNS offering is available, too, called OpenDNS VIP.

CLOUDFLARE: 1.1.1.1 & 1.0.0.1
Cloudflare built 1.1.1.1 to be the "fastest DNS service in the world" and will never log your IP address, never sell your data, and never use your data to target ads.

Primary DNS: 1.1.1.1
Secondary DNS: 1.0.0.1

They also have IPv6 public DNS servers:
Primary DNS: 2606:4700:4700::1111
Secondary DNS: 2606:4700:4700::1001

There's a 1.1.1.1 app for Android here and iOS here, for quick setup on mobile devices.

CLEANBROWSING: 185.228.168.9 & 185.228.169.9
CleanBrowsing has three free public DNS server options: a security filter, adult filter, and family filter. These are the DNS servers for the security filter, the most basic of the three that updates hourly to block malware and phishing sites:

Primary DNS: 185.228.168.9
Secondary DNS: 185.228.169.9

IPv6 is also supported:
Primary DNS: 2a0d:2a00:1::2
Secondary DNS: 2a0d:2a00:2::2

The CleanBrowsing adult filter (185.228.168.10) prevents access to adult domains, and the family filter (185.228.168.168) blocks proxies, VPNs, and mixed adult content. More features can be had at a price: CleanBrowsing Plans.

VERISIGN: 64.6.64.6 & 64.6.65.6
Verisign's public DNS services are centered around stability and security with 100% up-time, as well as privacy, citing that they "will not sell your public DNS data to third parties nor redirect your queries to serve you any ads."

Primary DNS: 64.6.64.6
Secondary DNS: 64.6.65.6

Verisign offers IPv6 public DNS servers as well:
Primary DNS: 2620:74:1b::1:1
Secondary DNS: 2620:74:1c::2:2.
There's a Check DNS Cache page on Verisign's website that you can use to check the current status of the public DNS, as well as an option to flush the public DNS cache.

ALTERNATE DNS: 198.101.242.72 & 23.253.163.53
Alternate DNS is a free public DNS service that blocks ads before they reach your network.

Primary DNS: 198.101.242.72
Secondary DNS: 23.253.163.53

Alternate DNS has IPv6 DNS servers, too:
Primary DNS: 2001:4800:780e:510:a8cf:392e:ff04:8982
Secondary DNS: 2001:4801:7825:103:be76:4eff:fe10:2e49

You can sign up for free from their signup page. There's also a Family Premium DNS option for $2.99 /month that blocks adult content.

ADGUARD DNS: 94.140.14.14 & 94.140.15.15
AdGuard DNS has two sets of DNS servers, both of which block ads in games, videos, apps, and web pages. The basic set of DNS servers are called the "Default" servers, and block not only ads but also malware and phishing websites:

Primary DNS: 94.140.14.14
Secondary DNS: 94.140.15.15

IPv6 is supported, too:
Primary DNS: 2a10:50c0::ad1:ff
Secondary DNS: 2a10:50c0::ad2:ff

There are also "Family protection" servers (94.140.14.15 and 2a10:50c0::bad1:ff) that block adult content plus everything included in the "Default" servers. Non-filtering servers are available if you're not interested in blocking anything: 94.140.14.140 and 2a10:50c0::1:ff