Monday, 23 October 2017

How to flush DNS cache on Linux and FreeBSD and Windows?

If I'm on a Linux/Unix system that does not run a DNS server 'named/bind/other' the system does not cache any DNS query.

In case when I run primary DNS and want to update zone information, I have change the serial in zone and restart service:

# /etc/rc.d/named restart (for named)
# rndc (for bind9)

To update zone information, check if I get a right DNS answer:

# dig @dns_server example.com

If I run a secondary DNS server I just get a copy of the zone from primary server and there is no point to flush cache. I can push the server update zone from the primary server by deleting the zone file and restarting your DNS service.

On Windows I have call next one:

> ipconfig /flushdns