Firefox invalidate dns cache [closed]
DNS caching occurs at multiple levels: Application asks local system, which asks locally configured resolving DNS server, which asks authoritative DNS servers.
Caching by Application varies.
- I've found for Firefox that quitting and restarting works. The relevant settings in
about:configarenetwork.dnsCacheEntriesandnetwork.dnsCacheExpiration, which can be set to0in order to disable caching.
Caching by local system is typically 1 hour.
- Diagnostic: ping, like other applications, uses local system DNS cache
- Flush MacOsX 10.8:
sudo killall -HUP mDNSResponder(reference)
(May vary for other versions) - Flush Windows:
ipconfig /flushdns(only if the DNS caching service,HKLM\SYSTEM\CurrentControlSet\Services\Dnscache, is enabled; check withnet start|findstr /i dnsorcompmgmt.msc) - Linux/Unix may use
nscd(name services caching daemon), ordnsmasq, or both ...
Caching by local resolving DNS server may run to several days, depending on TTL associated with DNS record.
- Diagnostic:
nslookupfirst reports address of resolving server, then address requested. - Flush BIND:
rndc flushorrndc flushname DOMAIN.NAME
TTL stands for "time to live" a term used to describe how long a DNS record is to be deemed valid by the requesting client or server. A short TTL means that the requester is told not to cache a DNS lookup for too long. The TTL can range from mere seconds (e.g. for DynDNS and similar) to days or weeks.
I've been using the "Clear Recent History\cache" solution for a while now, but I've noticed that it stopped working after one of firefox updates (probably 20.0.1). Because of that I've switched to https://addons.mozilla.org/en-US/firefox/addon/dns-cache/ add-on to do the DNS clearing. I hope this will help someone with the same problem.
Edit: Changed the url as suggested by Haozhun.
Edit2: Unfortunately as of FireFox 32, this plugin is no longer compatible and cannot be used. Possibly https://addons.mozilla.org/en-US/firefox/addon/dns-flusher/ might be able to replace it.