What Is DNS – The Domain Name System

What is DNS? A Guide to the Domain Name System

Think about the contacts saved in your phone. You find your plumber’s name, tap it, and your phone uses the number saved underneath. Handy when there’s water coming through the kitchen ceiling and you’ve got other things on your mind.

DNS does a similar job for website names.

You type wesh.uk into your browser because that’s the name you know. Your browser needs an address it can use to reach our website, though. That’s called an IP address.

DNS looks up that address. Your browser then uses it to connect to our website.

So, much like your phone’s contacts, DNS saves you having to remember a load of numbers just to get hold of someone.

The full name is Domain Name System. It also helps direct your business email to the right place, which we’ll get to shortly.

Why does DNS matter to your business?

You could spend a small fortune on a lovely website, but customers still need to be able to reach the bloody thing. DNS helps them get there when they use your domain name.

It also tells other email services where to deliver messages sent to your business. Get those details wrong and a customer’s enquiry might bounce straight back to them.

That’s why DNS needs some care when you change your website hosting or email provider. Your domain name can stay exactly the same, while the services behind it move somewhere else.

Think of your plumber changing their phone number. Their name hasn’t changed, but you’ll need to update the number in your contacts before you can ring them.

DNS needs the right details for much the same reason.

What are DNS records?

DNS needs to know where your website lives and which service handles your email. Those details are stored in separate entries called DNS records.

Your phone’s contacts can hold a home number, a work number and a mobile number for the same person. DNS records work along similar lines: one domain name can have different details for different jobs.

For example:

• Website records give your browser the address it needs to reach the website.
• Email records tell the sender’s email service where to deliver your incoming messages.

That means your website and email don’t have to be looked after by the same company. You could host your website with us and use another provider for your email.

Both can use your business domain name. DNS provides the directions for each.

How does DNS work when you visit a website?

If you type wesh.uk into your browser, you know which website you want, but your browser needs the address of the computer hosting it.

It asks DNS to look that up. Once it’s got the IP address, it can contact our web server and ask for the page. The server sends it over, and there’s our website on your screen.

You haven’t had to remember any numbers or faff about finding the right computer. You just typed our name.

Sometimes the address is already saved from a previous lookup. Your browser or the DNS service can reuse those details for a while, much as you’d keep a number handy if you knew you’d need it again.

This also explains something you might have come across when moving a website: it works from your phone, but your laptop still brings up the old one. They may be using different saved DNS details.

Why do DNS changes take time?

You’ve moved your website, the new details have been entered, and your mate says it looks lovely. Your screen still shows the old one. Marvellous.

That can happen because your browser or the DNS service it uses still has the old address saved. Your mate’s has picked up the new details.

Those saved DNS answers have a time limit. Until that runs out, they can carry on pointing to the old address. When a fresh lookup is needed, the new details can be collected.

You might hear this waiting period called DNS propagation. For a website address change, much of the wait is for those old saved answers to expire.

There’s no single waiting time that fits every change. It depends on what’s changed and how long the previous details could be kept.

The important bit is to check that the new details are correct. Waiting won’t fix a typing mistake, however many cups of tea you give it.

What happens when DNS goes wrong?

A missing record or a typing mistake can cause a surprising amount of grief. Two problems you might notice are:

Your website won’t open. Its DNS records might contain the wrong address, or a record needed to find it could be missing.

Your emails aren’t arriving. The records that tell other email services where to deliver your messages could be wrong or missing. This sometimes happens during a move if the new DNS setup hasn’t included the existing email details.

Mind you, DNS doesn’t deserve the blame for everything. A full mailbox can reject messages, and the server hosting your website can develop a fault even when the DNS details are spot on.

If something stops working, tell us what happens when you try to use it and whether anything has recently changed. Send over any error message as well.

That gives us somewhere sensible to start, instead of poking about and hoping we stumble across the problem.

How we look after your DNS at WESH UK

We run our DNS across several servers. If one develops a fault, the others can still answer requests for your domain’s details. That gives us some breathing room to deal with the problem while the remaining DNS servers carry on working.

We can also help when you need to change those details. Perhaps you’re moving your website, setting up a new email service, or following instructions from a supplier who seems to think everyone does this for a living.

Before changing anything, we need to know what you’re trying to achieve and what you already use. Moving your website, for example, doesn’t necessarily mean moving your email.

Checking that first can save you the headache of getting a lovely new website online, only to discover nobody’s receiving their emails.