How to organize two independent DCs in one physical network?

Question

Network administration

Good day, colleagues!
(possible implementations via VPN are not considered)
There was a need to raise, in addition to the existing domain, a second one, independent of the first one.
It is assumed that they will have a different subnet. Half of the users will subsequently move from the first to the second domain.
1. Whether cohabitation in one physical network of two such DC is real?
I assume that DC1 will be AD,DNS,DHCP, the second one will be just AD and DNS (there will be PCs on static IP)
(DC1 192.168.0.0/24 DC2 192.168.1.0/24)
2. If you set up trust between domains and all that, it’s real whether subsequently the transfer, or rather the complete migration of users from DC1 to DC2?
3. If user migration is possible, will the user profiles on the machines remain the same or will new ones be created?

Answer 1

1. Yes. You can even distribute DHCP settings to all PCs, only there must be trust between domains. The first domain controller will forward PC requests to the first controller of the second domain for authorization.
2. No, user migration (with SID) is not possible.
3. In the default option, new user profiles will be created. However, if you use the Profile Wizard program, then when transferring a PC from the first domain to the second, you can specify that such and such a user profile on the PC corresponds to such and such an account in the new domain. After that, the user will save all the settings of the desktop, programs, the location of shortcuts. Everything that requires certificates for work (CryptoPRO, client banks) will have to be reinstalled and registered again. Cached passwords in Credential Manager should be cleared out.