Dhcp is not dynamically updating dns
'usmdua8006' is the single label name for the system. A hostname can be a single label name of a node on a network or it can be a fully qualified name (example: 'usmdua8006.contoso.corp') If you look in the screenshot above, you will see that the LINUX hostname is a single label name.Viewing this from the DNS server displays the same issue.The lease duration can be customized to meet the requirements of your network.For example, if the number of IP addresses exceeds the number of DHCP clients on the network, you can configure a longer lease duration.
If the server from which the client originally leased the IP address does not respond, the client again attempts to renew the IP address when 87.5% of the lease duration has elapsed.If the zone is set to "Nonsecure and Secure" (allowing anonymous updates), every 15 minutes, the DNS record disappears. As seen in the verbose logs, every 15 minutes (the default), If the zone is nonsecure or set to "none " and the record does NOT exist, at step 3, DNS will create the DNS record (A(host) and PTR). **Note – Due to modern DNS client cache, the momentary delete / recreate of the DNS record is not noticed by clients.The DNS server will then discard the authentication token as it is not needed (the record was registered… SSSD will get the expected returned response of a successful authenticated update. They will continue to resolve the LINUX host throughout the process.What is even more confusing is the effect you see if the zone is set to "Nonsecure and Secure". This unexpected response to SSSD will generate an error. Hopefully this explains a number of scenarios and how to set to proper configuration.If the zone is set to "None", no update of any kind is done. To understand what happens here, you must look at the design of the DNS update process. Enjoy your more modern Linux dynamic DNS experience!