I've been running
ns2.acmehosting.com for several years as authoritative nameservers for several hundred domains. I've recently added
ns3.acmehosting.com, hosted in another data center.
I've updated the domain registration for
acmehosting.com and added
ns3 as a nameserver. I've added an
NS record to
ns3 has been fully configured (using
bind) as a slave and all my zones are loaded and responding properly.
Here's the puzzling part: of the hundreds of domains I host, I've only so far updated the registration and NS records for three of them:
As expected, when I run
dnstop, I see several queries for the above three domains. But I also see occasional queries, from a variety of client IP addresses, for other domains I host, even though I haven't yet updated their domain registration with
ns3 as a third nameserver, nor have I added the third
NS record to the zones for those domains.
Why are these domains getting queried, and how do clients even know to query
ns3 before I've updated the domain registrations or
Is it because
ns3.acmehosting.com has already been fully configured? Are clients somehow assuming/extrapolating that a third nameserver exists from the other available records?