MacMost Now 884: Using Alternative DNS

Every computer uses DNS servers to translate domain names to numerical addresses that can be used to find web pages. You can use the default DNS provided by your ISP, or you can choose your own. Sometimes you will see speed and quality improvements by using a public DNS instead of the default. Learn how to set your DNS in System Preferences and learn a potential pitfall of doing so.
Video Transcript / Captions
Closed captioning for this video is available on YouTube: MacMost Now 884: Using Alternative DNS.

Hi this is Gary with MacMost Now. On today's episode let's look at using alternative DNS servers.

Alternative DNS servers may sound a little advanced and really techie but it is actually kind of simple and useful for everybody.

DNS stands for domain name server and it is what translates a name, say or, into a set of numbers. A set of numbers is the real address of any web server. So when you type a domain name server translates that to the numerical address for that server and then your browser knows where to go to find that web page.

Now of course it wouldn't make sense for there to be one massive directory of all domain names and the numbers that they match. Because then everybody surfing everywhere on the internet would constantly be accessing that one server.

Instead they are distributed throughout the entire world. There are tons of duplicate copies of the domain name list. Basically all these servers access every few hours or every day the master list, bring that in, and then you have one that you can access. Usually if you have an ISP like say a cable provider or DSL provider they have their own list stored on they own server and every one of their customers accesses that list so that there is a limited number of people accessing that list not the whole world.

But there are also independent lists, ones that aren't tied to particular customers of a cable modem service, DSL, or maybe wireless service like you would get on your iPhone. These lists anybody can use. All you've got to know is how to tell your Mac or iOS device how to use one of these DNS servers rather than the default one.

See if you don't specify a domain name server here's what happens. Say you are hooked up through your cable modem provider. Well it is hooked up to the server and the server is going to suggest a DNS server to use, which will be the cable modem provider's own DNS server. So by default you are just going to go with theirs.

But if you specify a domain name server then you will use that one instead of the default one of your provider. Now why would you want to do this?

Well sometimes the one provided by your provider are not the fastest. So if every time it has to look up the name and translate to a number and it takes a second or a half second or a quarter second more and you are constantly accessing all sorts of different sites it could slow you down throughout the day.

At other times they are not as accurate. Maybe they are not updated as often and sometimes they are more prone to have errors in the list. So sometimes it is good to actually go with a third party one, a public open one that anybody can use.

So I'm going to show you two public DNS servers that I personally use. But there are plenty others out there. You can search for Public DNS and come up with a whole list.

Here is Goggle's and you can see there is a page guide. Just search for Goggle Public DNS and you come up with this. You can look and see right here on the page they give you the address. You need the address for these DNS servers. There is usually the main one and then a secondary one. Here are the two: 8888 and 8844.

Another one that you can use, and I've talked about this one before, is a service called OpenDNS that has been around for a long time. You can see it gives you the numbers here for their main and secondary domain name servers.

So you start off by just getting one or two sets of numbers like this. Then on your Mac you go to System Preferences and under System Preferences you go to Network and under Network you select the network that you are currently using. Then you click Advanced and under Advanced you will find DNS.

Here in DNS you can see you can add your own domain name server. Press the + symbol here and then you can add as many as you want. So I've actually added two of the Goggle ones and also the OpenDNS one there. But the one at the top is going to be the primary one that this Mac is going to use.

So if you frequently find that maybe browsing isn't as fast as you think it could be or that sometimes you can't get to a web site when you think you should, one of the things you might want to try is using one of these DNS services instead of just going to the default from your internet service provider.

Now there is one pitfall that I have encountered. Sometimes when traveling and trying to log onto wifi say at my hotel or conference center or airport it gives me instructions that seems to be very easy to get onto the wifi but I can't do it UNTIL I remove those DNS entries and use the default DNS because it is using DNS to basically redirect you when you first log on to the wifi to a page that gives you terms and conditions or you have to enter your room number or conference code or something like that. Once you do that then it will let you in and you have to kind of use their DNS to surf around or sometimes you can actually switch back to one of the other DNS's after you initially log in.

So it is something to keep in mind if you travel a lot that sometimes you are going to have to remove this when logging on to somebody else's wifi.

Another advantage of using a third party DNS is sometimes they can add features into it. So I encourage you to look at episode 453 of MacMost Now where I talk a little bit more about open DNS and how it can help you with more parental controls by blocking certain web sites at the DNS level.

So I hope you found this useful. Until next time this is Gary with MacMost Now.

Comments: 13 Responses to “MacMost Now 884: Using Alternative DNS”

    Doug Brace
    6 years ago

    It’s also possible to set the DNS servers on your router/modem. This will make it so you don’t have to go to every device on your home network and manually change the setting.

    John Roberts
    6 years ago

    I tried OpenDNS recently and found that I had trouble using it with iTunes Store and the Mac Apps Store. It wouldn’t connect to iCloud, either. It said there was an invalid site certificate.

    I switched back to the default DNS server and everything worked.

      6 years ago

      I’ve used OpenDNS with those before and have never had a problem.

        John Roberts
        6 years ago

        I’ve done a bit of searching and my guess is that it’s related to Comcast being my ISP.

    6 years ago

    Thanks Gary! I have used open DNS on my other non Mac computer. I wasn’t sure I could use it on a Mac. :)

    Morne Christou
    6 years ago

    I have an US iTunes account but at present I live in South Africa and want to use my Apple TV to view HULU % other services but can’t access the services. Can I use an open DNS server to allow my Apple TV to view HULU & other services in South Africa? If not do you have other suggestions. I know about “Hide My Ass” but this service requires a VPN router. I don’t want to replace my current router which is not a VPN router & therefore any other suggestions would be appreciated.

      6 years ago

      DNS doesn’t do that. It is like an address book for the Internet — it tells you computer where web sites are located, but it doesn’t change where you are located or where the site is located.
      You’ll need to use a VPN or VPN-like service for that. I don’t need those, so I don’t have any suggestions.

        Morne Christou
        6 years ago

        Perfect thank you Gary. Thanx for a great platform to learn about Apple products and features.

    Linda Lyn
    6 years ago

    Hi Gary
    Thank you for your teaching.
    If people would ask me where to find a good teacher to teach them how to use computer I will tell look up your website.
    Thank you so much.

    Yours sincerely Linda Lyn

    Mr Anthony Cotton
    6 years ago

    What you seem to suggest is the pitfalls of them both which is nice to know.
    Well thats another thing I will have a go with.
    I have never looked into the advanced section before incase I do something wrong and I would have a problem how to put it right Gary.

    6 years ago

    I switched the DNS on my iMac a couple of years ago to Google’s That greatly sped up my web browser(Safari). I’m trying to do the same on my wife’s MBP(OSX 10.5.8), without success. The self assigned DNS is greyed out and will not let me erase it. Any suggestions?

      6 years ago

      Hard to say without being there — and it has been years since I have used Leopard (10.5.X). Did you try just adding a new entry? Usually the default is there and grayed out until you add a new one.

        6 years ago

        Thanks for the reply Gary. Yes I did try and was successful in adding a new entry, but the self assigned DNS remained greyed out. After adding the new DNS, I tried dragging it to the top of the list, thinking that his would tell her MBP to prioritize I discovered the dragging feature is disabled.

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