Technical Tip: How to release DNS cache

[idabouzi]

Description	This article describes how to flush the DNS cache.
Scope	FortiSIEM.
Solution	After changing the DNS configuration in the FortiSIEM server, it is sometimes necessary to flush the DNS cache when restarting the NetworkManager service. To release the DNS cache: Make the required DNS changes: vim /etc/resolv.conf nameserver 8.8.8.8 Save and exit. Restart the following services: sudo systemctl restart systemd-resolved sudo systemd-resolve --flush-caches sudo systemctl restart nscd.service sudo systemctl restart NetworkManager Note: Ensure that port 53, Incoming/Outbound, is enabled. It is necessary to check any firewalls or security settings that may be restricting it. If this is Windows, host DNS cache can be flush using the below command in command prompt. ipconfig /flushdns Restart the phMonitor service: monctl stop monctl start