All computers and most mobile devices and routers let you point to DNS servers other than those provided by your ISP (Internet service provider). If you are having weird symptoms with your browser not loading the complete web page, or stalling at certain points, you might want to try alternate DNS. Symptoms include web page widgets not loading, such as Twitter embeds or Facebook embeds. You might notice an extra long time period while an ad loads, and you might see the ad server address show during the delay in the status box of your browser.
Choosing an alternate DNS
So-called public DNS providers offer DNS lookups that anyone can use. Switching to an alternate DNS requires a little tech operation, but there is no account set up, and it's free. There are two common alternatives -- OpenDNS and Google's Public DNS.
OpenDNS is the original DNS, beginning at a time when ISP-run DNS servers were very slow while your computer looked up the web address. OpenDNS sped things up by using an array of fast servers. Today OpenDNS has an array of servers with free-with-registration and paid add-on services for malware, threat protection, and network usage analysis. OpenDNS's DNS servers are 208.67.222.222 and 208.67.220.220.
Google’s Public DNS doesn't include the add-ons. Google's Public DNS is just DNS with the sleek numbers 8.8.8.8 and 8.8.4.4 for its DNS servers. There are additional public DNS servers, but these are the most common alternatives.
In most network configurations, an IP address and other network settings are provided from a DHCP (Dynamic Host Configuration Protocol) server on a local network via a router to all devices that connect for Internet access. One or more DNS servers is set this way. However, you can override this.
Public and ISP DNS providers typically give you two servers, that’s to handle a temporary failure or temporary overloading. One server usually works, but two gives you a backup in case the first one is having a problem.
Mac OS X
Open System Preferences and click Network.
Select your active adapter, such as Wi-Fi or ethernet.
Click Advanced.
Click the DNS tab.
Click the + sign at the bottom and type or paste in the first DNS server (e.g., 8.8.8.8). Then click + again to paste in the second (e.g., 8.8.4.4).
Click OK and then Apply.
Window 10
Right-Click on the monitor or Wi-Fi icon on the bottom right-hand corner, and Click on “Open Network and Sharing Center”.
Go to the active Internet connection
In the next window click on “Properties” button
Uncheck the “Internet Protocol Version 6” checkbox (6), then select “Internet Protocol Version 4 (TCP/IPv4)” and click on “Properties”
Select the “Use the following DNS server addresses” option and enter DNS Server addresses into the box for "Preferred DNS server" and "Alternate DNS server." You can find them in your Client Area -> VPN Packages -> your Smart DNS package or your VPN package that support Smart DNS service. Click “OK” .
Restart your computer.
See also ...
macworld.com/article/2930714/change-your-dns-to-avoid-or-bypass-broadband-outages-like-comcasts.html
zdnet.com/article/fixing-dns-woes-for-comcast-users-and-everyone-else/
