DNS Settings for 3 DCs

Question

HI,

I had a weird issue where i couldnt log into dc1, it kept saying my username / password is wrong. My account is part of the domain admins and i could log into dc2 and dc3. Upon reboot i was able to access dc1, which led me to think there is misconfiguration happening between the 3 DCs. Can someone confirm what the proper DNS settings should be for 3 Domain Controllers in one forest?

dc1 and dc2 are physically in datacenter1 and in the "Default-First-Site-Name" in Active Directory Sites and Services.

dc3 is in a different physical datacenter2 and respectively in a different site than "Default-First-Site-Name" in Active Directory Sites and Services.

Datacenter 1 and Datacenter 2 connect with a WAN leased 10Gig link so bandwidth is not an issue.

ALL 3 DCs provide DNS for redundancy and the settings are as follow.

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dc1 IP 10.0.0.130

DNS1: 10.0.0.131

DNS2: 10.0.0.130 <--- itself *should this be loopback address instead???

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dc2 IP 10.0.0.131

DNS1: 10.0.0.130

DNS2: 10.0.0.131 <--- itself *should this be loopback address instead???

---

dc3 IP 10.5.0.130

DNS1: 10.0.0.130 <--dc1

DNS2: 10.0.0.131<--dc2

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Is this proper configuration for DNS for all 3 DCs? I feel like as it is nothing is pointing to DC3.

I should also mention that we used openDNS as part of Cisco umbrella which delegates dns to the 3 DCs.

Any help would be greatly appreaciated.

Answer 1

Each domain controller should (at minimum) have its own static ip address plus loopback (127.0.0.1) listed for DNS

Might check the time is in sync for domain.

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

Answer 2

@Anonymous

So istead of OP it would look like this?

dc1 IP 10.0.0.130

DNS1: 10.0.0.131

DNS2: 127.0.0.1 <--- itself *should this be loopback address instead???

dc2 IP 10.0.0.131

DNS1: 10.0.0.130

DNS2: 127.0.0.1 <--- itself *should this be loopback address instead???

dc3 IP 10.5.0.130

DNS1: 10.0.0.130 <-- still confused as to where this one should point in Primary DNS

DNS2: 127.0.0.1

Could you confirm this is a proper setup in 3 DC enviorment?

Answer 3

So istead of OP it would look like this?
dc1 IP 10.0.0.130
DNS1: 10.0.0.131
DNS2: 127.0.0.1 <--- itself *should this be loopback address instead???

I'd at least add 10.0.0.130

dc2 IP 10.0.0.131
DNS1: 10.0.0.130
DNS2: 127.0.0.1 <--- itself *should this be loopback address instead???

I'd at least add10.0.0.131

dc3 IP 10.5.0.130
DNS1: 10.0.0.130 <-- still confused as to where this one should point in Primary DNS
DNS2: 127.0.0.1*

I'd at least add 10.5.0.130

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

Answer 4

So youre saying that i should have each DC point to itself as primary AND loopback as secondary?
What happens if DNS service stops on dc1 for whatever reason, and it receives a query? It appears that the request will stops and fail there since both DNS entries point to itself and service is not running.

Answer 5

What happens if DNS service stops on dc1 for whatever reason, and it receives a query?

Hopefully the client has more than one DNS server listed on it's own connection properties.

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