DNS question
 

How quick is DNS changing these days?

Few mins, usually.

If it's stuck in your DNS cache (ie. you've viewed / connected to the domain recently) it'll take a little longer. Few hours probably.

Depends on different factors such TTL (Time to live) and the individual ISP of the surfer. Generally a few hours for most. I'd plan on up to 24 hours to be on the safe side. Some ISPs are notoriously bad about it.

If server set properly and ISP updates his cache as well ... within minutes.

On your side, you can do ipconfig /flushdns to help .

most places few minutes will take a day to clear up the smaller isp's and older servers that are still online .

some of places in mins but i seen few times it take more than 12h

depends on ttl,

mostly within few minutes.

i remeber when it was 24-48 hours ;)

Do TTLs even matter anymore? I remember years ago, having to plan a server switch days in advance, because you need to switch the TTLs and let that propogate throughout the internet.

By default, the TTLs on most domains are set to 86400 seconds (24 hours), but doesn't seem to matter anymore though. Switch a domain, and it only takes minutes, and sometimes maybe hours at the most.

from IPv4 to IPv6 = major changes

TTL is just the refresh rate of cached DNS servers

I usually see about 24 hours max.

If you're using windows - flush your dns after changing nameservers

From the command prompt - ipconfig /flushdns

Few hours