How Do I Make DNS Requests to An Internal DNS Server for Site That Was Previously Hosted On Prem Route To A Site Off-Prem With A Diff URL?

This is embarrassing, but I'm hoping the hive can point me somewhere on this one.

I've got a domain that until recently pointed to an internally hosted site. Almost immediately prior to my taking over this position, that site was moved to managed hosting and given a new domain name (actually moved to a subpage on a different domain).

Here is my problem: Anyone using our internal DNS cannot get to the site using the old domain name, but external users can.

I've tried creating an ALIAS, and that did not work. Should I delete the whole DNS Scope now that it is off prem?

Does anyone else have any ideas?

Thanks in advance, and I'm sorry for the dumb question

P.S. I basically did this if that helps: https://www.youtube.com/watch?v=j9UysIvo1W8

The DNS is not split.

Edited to put the correct video in

It sounds like your internal DNS server has that domain configured on it, so the local DNS will consider itself authoritative for any requests it receives locally, whereas anyone external would query the public DNS servers.

If that's the case you likely have two options.

1. Replicate those new DNS records that have been setup for the new hosting on your local DNS server, so the records point to the correct destination. So for instance add the DNS records and subdomain used by the public website.

2. If that zone isn't used internally, for instance it's NOT the domain you use for your local AD, and has only been setup locally for that old website, and it doesn't hold any records pointing to internal resources that are still in use, then you could consider simple deleting the zone from within your local DNS server. That would make your local DNS server no longer consider itself authoritative for that domain, and it would then look to the public internet to find the answer to any requests for that domain, therefore directing internal users to the correct public IP.

Note, before attempting option 2 I'd check very carefully that nothing internal still uses it (if need be, turn on debug logging in DNS so you can see what is being requested from it), and make sure you have backups/exports/records of what was there previously in case you need to put it back later.

If the record is your local domain; like; example.com and example.com is your zone.

That would mean you can't erase the record or make a change easilly, but you could make it easy by configuring a www.example.com record that point to the external website, and to create on the DC that answer for example.com a local IIS that would do a example.com -> www.example.com 301 redirect.