Your DNS server is reachable, make sure forward and reverse lookup entries in your DNS server are correct. Forward Lookup A cucm.local 10.10.10.10 Reverse Lookup PTR 10.10.10.10 cucm.local Please rate if found helpful Regards, Aeby

If you use DHCP instead of a static IP address for vCenter Server, make sure that the vCenter Server computer name is updated in the domain name service (DNS). If you can ping the computer name, the name is updated in DNS. Ensure that the ESXi host management interface has a valid DNS resolution from the vCenter Server and all vSphere Web Client instances. DNS client unable to connect to name server - Dell Community 2) Select the "DNS Settings" tab. The same information (change in one location it "updates" the other) is also available from "CIFS" along the left, then the same "DNS Settings" tab. Not sure if you also are using the same DNS server for the Control Station, but it is a separate configuration as … DNS in Jail - not reachable from FreeNAS host? | iXsystems

Verify that the DNS Server service or DHCP Server service is running on the target server, and that the IPAM server has been successfully provisioned with Read access on the service ACLs. Also verify that remote service management ports are open on the target server. Problem: You are unable to make configuration changes on a DHCP server or scope.

DNS Requirements for vCenter Server and Platform Services If you use DHCP instead of a static IP address for vCenter Server, make sure that the vCenter Server computer name is updated in the domain name service (DNS). If you can ping the computer name, the name is updated in DNS. Ensure that the ESXi host management interface has a valid DNS resolution from the vCenter Server and all vSphere Web Client instances. DNS client unable to connect to name server - Dell Community

DNS Server Not Reachable Warning Message When Configuring

Allow Both TCP and UDP Port 53 to Your DNS Servers DNS queries are getting bigger so we do not want to accidentally block them Security practitioners for decades have advised people to limit DNS queries against their DNS servers to only use UDP