On Wed, 2022-02-23 at 08:23 -0800, Mike Wright wrote:
If you are using a hosted nameserver you will have to contact them and request a PTR record for 172.16.96.20 that points to centos8-opstcore-vm.homenet172-16-96.com.
I don't think you could use that with an external DNS, 172.16.0.0 is one of the private LAN IP ranges, and shouldn't be able to traverse a network.
Public and private IP address ranges
Class A: 10.0.0.0 — 10.255.255.255. Class B: 172.16.0.0 — 172.31.255.255. Class C: 192.168.0.0 — 192.168.255.255.
Of course they could have one of /those/ service providers which do NATing and don't give their clients public IPs, but they're uncommon. At least that range has about one million available addresses, class C only has about sixty-five thousand addresses (might not be enough for a very large ISP).
But generally speaking, anybody using those IP addresses needs to run a nameserver of some kind within their own LAN.