DNS: Website And Email Hosting
Do you know how it works?
POSTED BY PAUL MEAD ON 18/02/2019 @ 8:00AM
DNS is one of the key parts of what makes the internet world go round. Think of it of a big address book of servers ...
When you move web or mail host, the DNS servers around the world need to update!
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However, without a working DNS, a lot of the internet would simply stop working too. If you know how DNS works, then you will already be aware that when a website changes where it is hosted, or perhaps a change of where your email is hosted, then the DNS pointers (such as A records and MX records) will need to be updated.
"All around the world everyone's copy of the DNS information held on lots of separate servers for reliability and resilience is now out of date!"
If you ever change hosting provider and your IT company or web design people explain that it may take between a few hours to a couple of days for everyone around the world to see your new website, it is because of the DNS changes or DNS propagation (technospeak) that is happening, When that is complete (when all or most Internet Service Providers or Public DNS providers have up to date records), then your new website or email host should be rocking and rolling.
The big question most people ask me is, "how will we know when the changes have happened?" Well, given that there are many hundreds of thousands of DNS servers in the world, we cannot say with absolute certainty, but there are certain hierarchy (Google Root DNS) servers and timing (google TTL) arrangements that come in to play.
It is possible to manually query a DNS address book to check whether it still has the old or new information, but my tip today is to give you a website that will help you query this more easily which is called DNS Unlimited and it does a propagation check for you.
Pop in the name of your domain and the type of DNS record that you want to check and it will quickly go and make some DNS enquiries for you at different places around the world. This should help give you some idea as to whether your changes have started or are in progress, or have completed.
"Would you like to know more?"
If you'd like to find out more about DNS or are in need of more general IT support and assistance, do give me a call on 01604 420057 or click here to ping me an email and let's see how I can help you.
Until next time
More about Paul Mead ...
Paul is that rare type of IT geek that speaks plain English. Having played with computers all his life, starting with a ZX81, doing an IT degree, then working in IT support, Paul has managed to make his hobby his career.
He is often known to explain processes to clients using analogies like sock drawers and vehicle MOT’s to get difficult concepts over in easy to understand ways.
Paul is often seen running round Salcey Forest and participating in Triathlons when he isn’t glued to his desk.
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