ADDC for domain could not be contacted, because there are two domains and DNS for second (new DC) used to be point to old domains DC

Bjohn

7/17/24, 8:22 PM

I feel like this is a pretty simple question but I'm still little new to DNS. So the company I work for had an old Domain setup on a vlan that just wasn't worth the effort of saving so I created a new vlan and started a new domain but I wasn't ready to retire the old yet as there was still several offices using it. So, to keep old clients/services I bridged the two networks with a nic on each side of the domains and left DNS and DHCP on old network. I took a physical server setup with 2 nics one on vlan 1 and the other on vlan 2 both in DHCP. I then created a VM in hyperV to be my new domains DC and gave it 2 vnics each with an IP in each VLAN through the nic already connected to each vlan.

vN1 = x.x.x.19 in vlan 1(old domain), pref DNS pointed at itself x.x.x.19 and alt of Google.

vN2 x.x.x.2 in vlan 2(new domain), DNS pref was pointed at loopback(127.x.x.x) and alt was the old domains DC IP x.x.x.8.

This all worked and kept the domains separate so long as any client was "untagged" for appropriate Vlan of the domain they needed. Any new client on new domain had IP in new Vlan network lable of new domain name and a dns pointed at x.x.x.19(vlan 1)

I'm finally ready to start getting rid of old domain but I want to make sure I have some replication of my VMs prior to taking it down. I added new physical server put it on new domain, but HyperV manager will not connect to the existing srvs HyperV Manager. I realize this is because the original was never joined to the new domain (- only the vm was) and so there is a trust issue between the two HyperVs. I went to add the original srvr to the new domain and despite having a Nic on correct vlan and being on the new domain network, because the DNS is "not on the new domain" the AD DC join queries fail to reach the new domain. I feel like all I need to do is make the new domains' DC vN2 preferred DNS be the new domains DC IP x.x.x.2 and make alt the either Google or the Loopback but I hesitate to make this change as it was a small pain to make this work to begin with and as I said I'm still new to DNS. I'm still not entirely why DNS of new clients points to x.x.x.19 other than it is vNic on the DC. What are the consequences of making this change? is there a better solution?

0 + 1

active-directory

domain-controller

internal-dns

Bjohn

7/17/24, 8:25 PM

I did figure out how the x.x.x.19 was pointed to old DNS there is an addr-arpa record for it in new domains DNS records. but i do not see it directly relating to the old domain except that it is in vlan's ip range.

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: ADDC for domain could not be contacted, because there are two domains and DNS for second (new DC) used to be point to old domains DC

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.