We an an issue were when we failover a sql server clustered instance sometimes the server fqn servername.domain.com DNS Host A record entry will disappear. Has anyone had this issue and a fix?


2 Windows Server 2016 Clustered Server1.domain.com, Server2.domain.com 5 SQL Server instances in High Availability on the windows cluster

it does not happen everytime we failover sql server, but sometimes the server DNS host A records will disappear?

intermittently the dns records will disappear when we failover this cluster

  • Clarifying a couple of things. This is indeed an FCI and not an Availability Group? And when you say that the A record disappears, you get an NXDOMAIN response and not an A record that resolves to an IP address that doesn't respond?
    – Ben Thul
    Dec 19, 2022 at 20:00
  • Thank you for responding ben. It's a sql server availability group on a windows cluster two windows server 2016 servers in a windows cluster. When we failover the cluster the Host A record disappears sometimes. One thing to note is we previously changed all of our DNS records to static records to see if we could stop this behavior but it's still happening. Dec 20, 2022 at 21:06
  • Odd. I would start by checking your cluster logs around the time that the failover happens. And if that doesn't show anything, looking at AD logs. But I wouldn't expect the A record to disappear completely. During a failover, it should only be (at most) updating the IP address on an existing record.
    – Ben Thul
    Dec 20, 2022 at 21:25
  • a while ago we were having dns issues so we changed all of the dns entries from dynamic to static. do you think there is a process that is trying to update the dns entries and cannot do it deletes them? Dec 22, 2022 at 17:36
  • Maybe but feels weird to me. Like, why would the cluster service have permission to delete but not update? But also, I don't know that I'd manually change anything about the DNS record created by the AG - changing the underlying assumptions that the AG makes about the state of things feels like a "here be dragons" type thing. Also, how does the A record come back?
    – Ben Thul
    Dec 22, 2022 at 19:20


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