As you may know, vCSA is now running on Photon OS.
If you are performing some IP change on one of your ESXi, or you are adding a new ESXi on your infrastructure, you may struggle with DNS caching.
You may found on the web that the solution is simply to run this command on your vCSA :
systemctl restart systemd–resolved.service
Wich worked, on first release of vCSA 6.5, but not anymore.
If your go further in the vCSA configuration you will see in the /etc/resolv.conf this line :
nameserver 127.0.0.1
nameserver x.x.x.x
nameserver x.x.x.x
where x.x.x.x are your DNS servers. This configuration means that vCSA have a local DNS, thank’s to “dnsmasq”
In order, to clear the local caching you’ll need to restart the dnsmasq service thank’s to this command:
systemctl restart dnsmasq
those will not perform any side effect on your infrastructure.
Feel free to leave a comment if you’re still in struggle with DNS on your vCSA.