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Before I embark on the experiment, I figured I might ask the community at large.

So I've got an odd situation that I'm trying to remedy. I have Terraform deploying virtual machines (Linux and Windows) into an on-premise datacenter (VMWare) with an Infrastructure predominant Windows (AD, AD-DNS, etc.). TF deploys the VMs into a DHCP VLAN with dynamic DNS, but when the host is re-deployed, the DHCP lease sticks around, and causes issue with the DNS record getting updated.

What I'm looking to do is deploy PowerDNS as a DNS server (since it has a Terraform Provider), and utilize that not as it's own Zone, but as a slave to the AD Integrated DNS Zone.

Before I spend a day or two tinkering with this, does anyone out there use PowerDNS to update DNS records in an AD Integrated DNS Zone? My google-fu isn't giving me much clarity on which directions I can update.

DavisTasar
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1 Answers1

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I don't really see how introducing a third-party DNS solution is going to help your situation.

  • Is it a Windows DHCP solution?
  • Are both Windows and Linux clients affected?
  • What's the DHCP lease interval? (Hint: is it longer than the interval you typically "recycle" machines? e.g. you redeploy machines daily, but your leases are 7 days)
  • Are you redeploying the same machines to the same subnets and if so, have you considered reservations? (Yes, some admin overhead setting it up, but it can be scripted and it takes care of itself if you ensure stale reservations are removed regularly.)
  • If it's Windows DHCP, are the options Always dynamically update DNS A and PTR records and Discard A and PTR records when lease is deleted enabled? (Not sure how that might work with Linux clients, it's been a while.)
  • Finally, what's the no refresh interval in the Aging properties for the DNS zone? Hint: is it greater than the DHCP lease interval?

And some resources:

  • The main Microsoft article on configuring dynamic DNS, with reference to Windows DHCP.
  • This article describes the no-refresh and refresh intervals on Windows DNS and how that works with scavenging. The records don't need to be scavenged to be refreshed (as long the record age has exceeded the no-refresh interval). But if you don't want confusing records cluttering up DNS, set these all to fairly low intervals, as in hours rather than days.
LeeM
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