I've seen similar issues (years ago) where some ISPs didn't honour DNS TTLs, and would instead cache the results a LOT longer.
On Mon, Oct 7, 2019 at 9:08 AM Mike <mike-na...@tiedyenetworks.com> wrote: > Hello, > > > I am moving a number of web sites from one colo to another, > re-numbering them in the process, and I have run into an interesting > issue I'd like to solicit feedback on. > > My dns TTL's are all 300 seconds, and I have noticed that once I > update the A records with the new addresses, most (but not all) web > clients begin using the new address within 5 minutes or so. However, > there is a persistent set of stragglers who continue accessing the > site(s) on their old addresses for far in excess of this - up to a week > in fact. And, what I have noted, all of these clients have something in > common - they all appear to be satellite users of viasat/exede. This is > based on whois lookups of the ip addresses of the clients. Note, I am > NOT expecting 'turn on a time' - just looking for clients to refresh > within a reasonable time. > > I am wondering if perhaps this is due to some kind of (known?) > bug in the embedded dns cache/client in the client satellite modem, or > if there is another plausible explanation I am not seeing. It compounds > my problem slightly since I have to continue running the web sites at > both the old and new addresses while these things time out I guess and > it's just inconvenient. > > > Thanks. > > > MIke- > >