Why this matters
Sometimes users say "WhatsApp works but no websites open" or "the internet works but our company portal does not". These half working problems are often DNS problems. IT support adverts in Ghana ask for network troubleshooting and configuration, and DNS is one of the first things an experienced technician checks.
What DNS does
Computers reach each other using IP addresses, but people remember names. DNS (the Domain Name System) is the internet's directory: it turns a name such as example.com into the IP address of the server that hosts it.
When you type a website name:
- Your device checks whether it already knows the answer (it keeps a short memory called a cache).
- If not, it asks its DNS server, usually given by the router through DHCP. This may be the internet provider's server or a public one.
- That server finds the answer, asking other DNS servers across the internet if needed, and replies with the address.
- Your device connects to that address.
All this usually takes a fraction of a second.
Records you will hear about
- A record: links a name to an IPv4 address (AAAA does the same for IPv6).
- MX record: says which server receives email for a domain. When an organisation moves its email to a new provider, MX records change.
- CNAME: an alias pointing one name at another.