I have an existing case open with support (case #00820404). I'm posting here to see if anyone has the appropriate logging set up to see if the same issue exists in their environment.
A brief description of my environment: 2 sites. Site A has a server running VeeamONE, and a Veeam B&R server (veeam01) that's backing up a vSphere environment. Site B has a server (veeam02) that's the target for Backup Copy jobs from Site A. Veeam01 and Veeam02 are each functioning as Proxy, Repository, and WAN Accelerator for each site. VeeamONE and Veeam B&R are all at current patch levels (8.0 + Patch 1). All three servers (VeeamONE, veeam01, and veeam02) are Windows 2008 R2.
The issue: Our VeeamONE server sends approximately 190 queries (sometimes a few more, sometimes a few less) to DNS, every single minute, to resolve the IP of Veeam01. It also sends approximately 100 queries, every minute, to resolve the IP of Veeam02. This happens regardless of there being entries in the VeeamONE server's local DNS cache. Originally, I thought the flood of queries was happening only when the TTL for the cached lookup expired on the VeeamONE host, but I pulled my DNS logs into Splunk to drill into the data and have proven that to be false (and I just shared that last piece of info with Support today).
I've run a packet capture on the VeeamONE host to take a look at the traffic and confirm that responses from our DNS server are happening in a timely manner, and the host does not continue to send requests because it's not getting a reply. Looking at the DNS traffic in the pcap, each request is followed immediately by the response (so, in chronological order it is always Request, Response, Request, Response, etc.).
If I stop the Veeam ONE Monitor Server service, the queries stop. As soon as the service is started again, the flood of 300ish queries per minute starts again.
This isn't causing any particular problem in my environment. It's not creating a DoS condition on the DNS server or anything like that. But it is certainly not normal for an application to be doing this.
If anyone reading this logs DNS requests in their environment, can you check to see if your VeeamONE server is also exhibiting the same problem? Or if you're not logging DNS requests, but have some time to kill and feel like running a packet capture on the VeeamONE server to look at the traffic.
Support has told me that they don't see the same behavior in their environment.