vCenter Server 6.x versions prior to 6.7 Update 3 does not support changing the PNID after deployment.
Symptoms:
If hostname and DNS configuration reverts to original values after rebooting the VCSA machine see VMware vCenter Server Appliance hostname and DNS configuration revert after a reboot (2122383).
Also see, How to update content libraries after changing vCenter Server PNID
To change the IP address of vCenter Server that was deployed with a FQDN PNID:
To verify the current PNID, run the following commands in VCSA or Windows vCenter Server respectively:
VCSA: /usr/lib/vmware-vmafd/bin/vmafd-cli get-pnid --server-name localhost
Windows: "C:\Program Files\VMware\vCenter Server\vmafdd\vmafd-cli.exe" get-pnid --server-name localhost
Workaround:
Note: On rare occasions, you may need to manually set and complete the PNID change via the command line should the above UI workflows incompletely set the PNID.
To set the PNID via CLI:
VCSA: /usr/lib/vmware-vmafd/bin/vmafd-cli set-pnid --server-name localhost --pnid <PNID-NAME>
Warning: If you attempt to set the PNID via the command line only without going through the proper workflow, as mentioned in the Resolution section, you may break vCenter.