How to flush DNS cache in Linux? Similar to what you can do in Windows with this command:
Different Linux flavours may run different DNS daemons, like nscd or BIND or dnsmasq. Each may have its own way of flushing its cache. Usually DNS cache is being reset by simply restarting the corresponding daemon.
For example, here is how to flush DNS cache by restarting nscd in Redhat:
service nscd restart