So I migrated a mediawiki site to a new Server. The old one is still up but the database is locked and I merge the new Content with rsync and mysqldump every 15 min. So we can read the content from the old IP.
Now I changed the A record of the domain to point to the new server. After 3 hours and when I am using a cache cleared browser, I am at the new server.
However, when I am using an not cache cleared browser, I am landing at the old server.
How to tell the browser, that it should clear its dns cache, or that there is an IP change?