DNS Cache – How Often Does DNS Cache Clear on Windows 7
cachednswindows 7
How often does the DNS cache clear on a Windows 7 machine?
Best Answer
The DNS cache doesn't ever flush, unless you explicitly tell it to or you make a DNS/networking related configuration change. DNS records have a Time To Live (TTL) value associated with them which tells a DNS cache how long the particular record is good for. Records in the cache are kept for their TTL, then re-queried.
On a Windows machine you can see a list of all the records in your cache along with their TTL by executing the following command at the command prompt:
ipconfig /displaydns
You can force a flush of all cached DNS records using the following command:
Øhh, ubuntu doesn't cache DNS per default. So there is nothing to flush! (but maybe your SOHO router does). Installing nscd will make ubuntu cache DNS, afterwhich you can clear your cache - but this is besides the point, when you don't have it installed yet!
Best Answer
The DNS cache doesn't ever flush, unless you explicitly tell it to or you make a DNS/networking related configuration change. DNS records have a Time To Live (TTL) value associated with them which tells a DNS cache how long the particular record is good for. Records in the cache are kept for their TTL, then re-queried.
On a Windows machine you can see a list of all the records in your cache along with their TTL by executing the following command at the command prompt:
You can force a flush of all cached DNS records using the following command:
For more info: