Have you heard the expression “it’s is always DNS”? Well it is true. I found myself in this situation a few days ago and it reminded me it was time to regale you with another blog post!
Are you having trouble connecting to a site or service over the internet? You have tried all the steps to troubleshoot your environment but you still can’t connect. For example, you have rebooted all your internet equipment, cleared app caches, reinstalled the app, updated the app or service or maybe even prayed to the Internet gods to rectify things (that last one was a joke).
Before I go through the 3 Ways to fix DNS issues, lets briefly discuss what DNS is in the first place.
DNS is a Directory / IP Address Translation Service
I like to use the analogy that DNS is like a phonebook but in reverse. You need to find out someone’s telephone number so you look up their name. With DNS you know the name but the app or service you are using needs to know the number to be able to connect. You see computers are great with numbers (like IP addresses) and humans are great at names (like cayville.ca). DNS, like a phone book ,is great at bridging the gap.
So when you type a website into your browser or open an app on your phone or tv box etc. , it resolves to an IP address that connects you to the service on the Internet. Sometimes the IP address changes for a particular site and DNS needs to update to reflect the change. This could be instantaneous or take a few hours or days. There are DNS servers all over the Internet and they have to update (a process known as propagation). Now here are the three ways you can fix this problem.
All deal with flushing the DNS cache which will force updates if certain DNS names have changed IP’s but where?
Clear Browser Cache
Your browser stores lots of info about the websites you visit. It could be as simple as clearing it and the website or service you are connecting will start to render properly. Here are instructions for the most popular web browsers:
Flush Your Devices DNS Cache
You device will have a DNS list cached locally on your device. It updates regularly but sometimes it doesn’t. You can flush it by dropping down to a command prompt (Windows) and typing “ipconfig /flushdns”. In Linux “$ sudo systemd-resolve –flush-caches” , then ” $ sudo resolvectl flush-caches”. You will have to consult your Linux flavor’s documentation for exact syntax. Same goes for MacOS.
Another quick way if you are connected to Wifi is forget the Wifi network and reconnect to it. DHCP will take care of the rest and refresh the DNS settings.
Flush Local DNS Server Cache
This is for the intermediate user. If you run a local DNS server on your network it is mainly used to resolve your local network’s domain names. If a device on your network needs to resolve an address outside your network (probably 99.99999% of the time) it has been set up with a forwarder. This will happen when the same site or site is not working on all of the devices on your network. Flushing your local DNS servers cache will fix this. Depending on what local DNS server software you use it will be a different procedure. However, it is quite simple; restart the the service.
So remember, no matter what the issue is when having Internet connectivity problems, if it isn’t something physical like a cut cable, dead modem / router / switch, it is always DNS!
Happy IT’ing
Dan
Dan
I am an IT professional with over twenty years experience in the field. I have supported thousands of users over the years. The organizations I have worked for range in size from one person to hundreds of people. I have performed support from Help Desk, Network / Cloud Administration, Network Support, Application Support, Implementation and Security.