What DNS Is and Why Changes Take Time
DNS, the domain name system, is the global directory that turns domain names into the addresses computers use. Every time someone visits your site or you receive an email, DNS quietly does its work in the background.
One question we hear constantly is why DNS changes are not instant. The answer is caching — a deliberate design choice that keeps the internet fast but means updates spread gradually.
A Distributed Address Book
There is no single DNS server. Instead, thousands of servers around the world hold copies of records and pass queries along until an authoritative answer is found.
Why Changes Are Not Instant
To avoid asking the same question millions of times, servers remember answers for a while. That stored answer is only refreshed when it expires.
- You update a record with the new value.
- Servers that already cached the old value keep using it until their stored copy expires.
- As each cache expires, it fetches the fresh value.
- Once every cache has refreshed, the change is fully live.
Planning Around the Delay
Because of this behaviour we plan important DNS changes in advance, lowering the cache lifetime beforehand so the switch happens quickly and predictably when it matters.
If you need a hand with any of this, your Progressive Robot delivery team is ready to help. Raise a ticket from the Support area of your client portal or speak to your account manager and we will guide you through the next steps.