Can domain records exist in multiple registrars?

Question

I have a client that wants to maintain control of his domain (fair enough) - he also wants to maintain control of his MX records (fair enough).

He is with CrazyDomains and the current records kind of look like this:

Before

CrazyDomains:

• A Name: @ 111.222.333.444
• MX: 1ASPMX.L.GOOGLE.COM
• MX: 2ASPMX.L.GOOGLE.COM
• DS: ns1.crazydomains.com
• DS: ns2.crazydomains.com

After

CrazyDomains:

• MX: 1ASPMX.L.GOOGLE.COM
• MX: 2ASPMX.L.GOOGLE.COM
• DS: ns1.crazydomains.com (for MX records)
• DS: ns2.crazydomains.com ( "" )
• DS: ns1.digitalocean.com. (for AName records)
• DS: ns2.digitalocean.com. ( "" )

Digital Ocean (I control via Network tab):

• A Name: @ 666.777.888.999

Essentially I can maintain the A Name records (via Digital Ocean) and he can maintain the MX records (via CrazyDomain).

Alternatively - is it possible to set a static ip, that I can map onto different servers, without the client needing to update their records. Digital Ocean has floating IP's - but they must point to DO instances.

Answer 1

Can I maintain the A Name records (via Digital Ocean) and he can maintain the MX records (via CrazyDomain)?

No.

Or rather an authoritative name server must hold the complete zone info and can't be configured successfully such that A records are on a different DNS server from the MX records.

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When as a hosting provider you need to be able to (frequently) change ip-addresses and you don't have full control of the domains your customers use, the typical solution is that as the hosting provider you ask the domain owner to set up a CNAME record to a hostname in a domain that you do control completely.

Your customer sets up www.example.com. IN CNAME customer-xyz.hostingprovider.example. and will only have to do that once.

In turn you point customer-xyz.hostingprovider.example. to the correct ip-address with an A record and can change that as frequently as needed without needing any intervention from your customer(s).