It's the cache. Each record has a lifetime to avoid hammering of the authoritative NS.
3 Likes
Note that the big value of using a big central caching DNS server is that it eliminates the need to keep re-querying records with very short TTLs of a few seconds, such as those a lot of web developers use for dynamic parts of their web pages. An alternative is to use a local DNS server that can enforce a minimum TTL, such as several minutes.
Technical details: https://blog.apnic.net/2019/11/12/stop-using-ridiculously-low-dns-ttls/
Seeing the conversation, I think it would be worth for many participants to know the downsides of a global DNS services.
- Privacy. Your ISP can track you anyway, now you suddenly provide a lot more information to google or other organizations.
- Zoning. When you resolve a name, many DNS servers would return to you a different result depending on your IP address, so that you access a server physically closer to you. If you use a global service, you will get a server that is physically close to the global service, not yourself thus potentially reducing connection quality.
Unless I see unreasonable delays or problems, I use my ISP DNS servers. Presently I run a resolving unbound DNS server because my ISP's servers sometimes just stop working properly and don't believe there i any problem with that.
My guess is that by default chrome uses the global google DNS, so most people can't notice a few minutes hiccups of their servers.
1 Like
This topic was automatically closed 10 days after the last reply. New replies are no longer allowed.