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dual redundant DCs no longer update reverse lookup zone info from secondary DHCP

Configuration:
primary site:
- two (2)  DCs (2008 R2 domain controllers) configured for redundancy on 172.16.10 subnet
- DNS integrated with AD (Active Directory)
- SOA (Start of Authority) here for entire domain

two (2) remote sites:
- two (2) remote locations 172.16.20 & 172.16.30
- single 2008 R2 server at each site with mainly IP devices
- both remote locations have secondary DNS servers and local DHCP
- DHCP configured to point to primary site DCs as DNS

Functionality we had:
- when we had one (1) DC at primary site (172.16.10) - DHCP updates at secondary sites (172.16.20 & 172.16.30) would show up in "reverse lookup zones" in the DNS of the primary site (172.16.10)  ... this allowed primary site to know dynamic IP addresses of secondary sites remote devices

This functionality was lost when we added second (2) DC to the primary site.  Changes by remote secondary sites' DHCP (172.16.20 & 172.16.30) are no longer seen in primary site (172.16.10) DNS "reverse lookup zones"

How do we configure so we have the desired functionality with redundant primary DCs?

Thanks in advance for your help
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wmhooper
Asked:
wmhooper
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1 Solution
 
footechCommented:
Why not use AD-integrated zones at all sites, and point machines at remote sites to use the local DNS server?  Replication can handle getting all the information to all the DNS servers.

How are the reverse zones configured?  Are they AD-integrated?  If so, are they configured to allow only secure dynamic updates, or what?  For secure zones, since it is the DHCP server that registers the PTR records for dynamic clients, I would check the credentials that you are using.
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wmhooperAuthor Commented:
The remote sites are warehouses, with RF devices and single servers - insecure sites from an IT perspective.

The company only wants domain controllers in the central location, plus the disaster recovery location (the reason for the two (2) primary DCs)

Further research on this problem seems to point to the need to have one DC as read / write and the second DC be ReadOnly and not have both DCs as read/write

We may try this option in few months if we can not get the current configuration working as required.
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wmhooperAuthor Commented:
From footech:

Q1: How are the reverse zones configured?  Are they AD-integrated?  If so, are they configured to allow only secure dynamic updates, or what?  

A1:The two DCs with reverse zones are AD-integrated. They were configured for secure updates but we also tried to allow for un-secure updates as a test.

Q2: For secure zones, since it is the DHCP server that registers the PTR records for dynamic clients, I would check the credentials that you are using.

A2: The dynamic updates from remote DHCP to the reverse zones on the DCs worked when we only had a single DC.

The introduction of a second redundant DC (at disaster backup site) broke this functionality.
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footechCommented:
At the most basic, there's no reason (that I can think of) that just adding another DC would impact DNS records registration.  In my experience, problems with records registration almost always stem from security configuration, resulting in records that cannot be updated due to the record's ownership.
The best recommendation I have is that you configure all DHCP servers to use the same domain account to perform DNS dynamic updates (under Advanced tab > Credentials), and to add all DHCP server accounts to the DNSUpdateProxy group in AD.

See this link for further details.
http://msmvps.com/blogs/acefekay/archive/2009/08/20/dhcp-dynamic-dns-updates-scavenging-static-entries-amp-timestamps-and-the-dnsproxyupdate-group.aspx
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