I hate the term "DNS propagation". It confuses people, and makes them think things that aren't true, like a new domain isn't usable until it "propagates" through the Internet.
We tell clients that we've launched their site, but that the DNS changes might take up to 48 hours to propagate.
Realistically, from our office and to most of the world it's probably live within 5 minutes. One of our local ISPs happens to be one of those irritating ones that just ignores your TTL and caches records for days at a time.
Sometimes one of their servers will end up with the new record and one with the old. That combined with peoples' home routers caching records (again, sometimes ignoring TTLs) can lead to fun situations where the site might load fine for a couple hours (hit the good ISP server, local router cached) then the old site for a couple of hours (hit the bad server, local router cached...).
I used to try and explain it to people but after having enough people freak out about how their site switched back, it's not live yet, etc, etc... I just tell them it's going to take 48 hours. If it's visible earlier it's a pleasant surprise, and if it takes two days I don't get any panicked phone calls.
We tell clients that we've launched their site, but that the DNS changes might take up to 48 hours to propagate.
Realistically, from our office and to most of the world it's probably live within 5 minutes. One of our local ISPs happens to be one of those irritating ones that just ignores your TTL and caches records for days at a time.
Sometimes one of their servers will end up with the new record and one with the old. That combined with peoples' home routers caching records (again, sometimes ignoring TTLs) can lead to fun situations where the site might load fine for a couple hours (hit the good ISP server, local router cached) then the old site for a couple of hours (hit the bad server, local router cached...).
I used to try and explain it to people but after having enough people freak out about how their site switched back, it's not live yet, etc, etc... I just tell them it's going to take 48 hours. If it's visible earlier it's a pleasant surprise, and if it takes two days I don't get any panicked phone calls.