florian

Clear DNS cache on vCSA 6.5 and later

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 systemdresolved.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.

 

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