DNS – Switching your Website Hosting

I was talking with a good friend of mine last night about the issues we have had over the years when some businesses have switched their website to different hosting, and the disasters that have ensued when it hasn’t been carried out properly. I said I would write about it – so here it is.

This post definitely falls under the category ‘technical’ rather than ‘design’, but reinforces my view that those working with websites benefit from having technology skills along with design skills in the online world. I have lost count over the years how many times a business has had to recover from downtime caused by getting changes to DNS wrong when a website has been moved to new hosting.

What is DNS and why is it important?

DNS stands for Domain Name System. For the purposes of websites it acts as a translation service between the words that make up the website addresses we are familiar with, e.g. www.meemodigital.com and what the internet is actually based on – IP addresses.

There is a process that occurs when someone types the address into their browser bar, or clicks on a link from a search engine to your website so they end up with the correct website being presented. Lookups are made to discover the answers, queries are carried out to determine which servers handle the translation services for your domain. The server which controls the DNS services for a domain is referred to as a nameserver.

A nameserver holds the DNS records for your domain. There are DNS records that relate to your website. When a query is made against the nameserver the correct server that hosts your website is delivered as a result and you can successfully browse to your desired website. This process goes on in the background when we navigate to a website, so all we see as a user is the presentation of the words – the result of the translation.

Where it goes wrong

If someone is only concerned with websites and doesn’t understand DNS then you can be on dangerous ground. Nameservers handle DNS queries for a domain regarding a number of different services, in addition to just providing a translation service so we can navigate to a website.

The simplest example is records relating to your emails. When you send an email to a domain, the nameserver for that domain is queried and serves up results that enable our emails to find the correct destination.

So where does the process often go wrong when a website is moved from one host to another? Changing the nameservers and not just the DNS records necessary for the website. Ignoring all of the other records that are being served up on the existing nameserver.

DNS changes are not instant, they take time to propagate and are cached, so you end up in a situation a little while later where businesses are wondering why they are not receiving any emails. Even when you get the records back you have to wait for the system to update. It can take a while to resolve and have negative consequences for your business.

How do you avoid problems?

Change the DNS records for the website and not the nameservers wherever possible.

If you do wish to change nameservers, make sure ALL the existing DNS records are in place on the new nameservers for a domain BEFORE you switch over the nameservers in the control panel for your domain.

Don’t just assume that DNS records for email will be the only other records in place. Get a full copy of the DNS records for the domain before your switch the nameserver, to avoid headaches with any other services that rely upon DNS to work.

As a side issue be aware that all DNS service providers are not created equal and some are more reliable than others. Effectively, if your DNS is down for your website then your website is down. Where the site is hosted may be working fine but if your DNS is down nobody can reach it. DNS is a favourite target of those with malicious intentions on the internet. A common cause of disruption is to create a distributed denial of service, (DDoS) attack which overwhelms the DNS server effectively putting it out of action. This is what happened with Twitter recently.

If you would like assistance with moving your website to new hosting, get in touch.