What you change
DNS is your domain's address book. It lives at one company (often where you bought the domain, sometimes your old web host). You change:
- A record for
@(your domain itself) →2.25.245.213 - www → a CNAME to yourdomain.com (or an A record to
2.25.245.213) - Delete any AAAA records on
@andwww
The www entry usually exists already as a CNAME, so you change it rather than add a new one: most screens refuse a second www entry.
Why delete AAAA? They are your old host's IPv6 addresses. Left in place, some visitors still see the old site and the padlock certificate can't be issued.