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When a website's nameserver is set to point to a new IP address, do the cached html pages and images in the user's browser invalidate and get re-fetched?

Consider this case:

  1. The nameserver's A record's TTL is 5 minutes.

  2. The website's HTML, js and image cache has a TTL of 1 hour.

  3. The nameserver's A record is changed to another IP address.

  4. 10 minutes later a returning user (who has the website cached in his browser) accesses the website.

My understanding is that the user's browser checks its DNS cache, sees that the TTL expired and will re-fetch the website's IP from the internet.

Once all nameservers in the chain honor the TTL, the user's browser receives the website's new IP address.

Would the HTML, JS files and images cached in the user's browser all be refetched from the new IP address, even though their TTL hasn't expired (their TTL is 1 hour)?

I'd like to generally know how the user's browser cache responds to the website's IP address changing.

I've searched this site and across the web and can't get a clear answer for this.

Peter Henry
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1 Answers1

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The cache looks for URL hits. http://example.com/foo.js is still http://example.com/foo.js if the IP of example.com changes.

Many sites do load balancing with DNS, where a single name may have many A records.

vidarlo
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