How domain joined pc look for random domain controller if domain controllers in one site totally down

Question

Just trying to understand more on this, assume that we have two AD site, site A and site B. Each site has two domain controllers with DNS. For client machine in each site the DNS server entries are configured for the site domain controllers. For example:

Site A is having domain controller 1 and 2. Site B is having domain controller 3 and 4. User machine is site A is configured with DNS server entries of domain controller 1 and 2. Then for site B machine the DNS is configured for domain controller 3 and 4.

In this case, if site A both domain controllers were down and the user machine in site A can still ping to site B domain controller. How the user machine look for domain controllers in site B automatically since both the DNS server entries were down? Will the machine cache the list of domain controllers in the first place during the DNS record lookup?

Answer 1

Yes, it still can work.
https://social.technet.microsoft.com/wiki/contents/articles/24457.how-domain-controllers-are-located-in-windows.aspx

--please don't forget to upvote and Accept as answer if the reply is helpful--

Answer 2

You can read here about the domain controller location process.
https://techcommunity.microsoft.com/t5/ask-the-directory-services-team/domain-locator-across-a-forest-trust/ba-p/395689

--please don't forget to upvote and Accept as answer if the reply is helpful--

Answer 3

Hi,
I am glad to hear that your issue was successfully resolved. If there is anything else we can do for you, please feel free to post in the forum.
Best Regards,
Vicky