Comments on: How to flush DNS cache in Linux / Windows / Mac

By: captain

captain — Wed, 10 Mar 2010 17:38:26 +0000

I believe you have the instructions for OSX and OSX-Leopard+ backwards. dscacheutil -flushcache is used in Leopard and SnowLeopard.

By: Ammad

Ammad — Wed, 06 Jan 2010 06:39:39 +0000

its not working on RHEL, enen though i have restarted, named, network service and nsdc.

thanks

By: hic

hic — Wed, 12 Aug 2009 18:21:58 +0000

even tried lookupd -flushcache, still aint working.

By: hic

hic — Wed, 12 Aug 2009 18:21:32 +0000

i cant seem to flush on my mac 10.4
typed in dscacheutil -flushcache in terminal
but says, command not found?

By: Tricky

Tricky — Sun, 26 Apr 2009 23:25:43 +0000

@Dad, kyle, daftwill123, and SoGua: should probably be *restart* the “DNS Client” service. If it isn’t already started then the service would have been disabled and there’s nothing to flush. Best to also check that the service is set to start on startup within the Right-click Properties dialog box.

@sweet bunny: I don’t believe any Windows versions prior to Windows 2000 did any caching at all without specifically installing a DNS caching service. Chances are the issue was with an upstream DNS server or maybe your firefox cache as per. See below or SoGua’s comment from August 7th 2007.

Re nscd, many *nix distros don’t have nscd installed by default. If “nscd -i hosts” doesn’t clear the cache (that’s the correct way to flush it btw) then installing it won’t help you except to install an empty cache. Also, there could be other daemons installed instead of nscd, dnsmasq or bind for example (Bind is generally not the best for a desktop – but is still installed on a lot of servers). Bind’s cache can be flushed with “rndc flush”. Dnsmasq I believe has to be restarted for the cache to be flushed.

Lastly, there’s also a lot of upstream cached records that might be totally outside of your control. In case your current DNS server has the incorrect info cached, try changing your caching DNS server settings in your Network Settings to use a different server.

By: daftwill123

daftwill123 — Mon, 13 Apr 2009 02:34:59 +0000

Thank you!!!

By: SoGua

SoGua — Mon, 06 Apr 2009 03:00:33 +0000

Ok here’s another solution: Go to Control Panel -> Administrative tools -> Services and look for “DNS Client” and right click on it and Select Start. Once DNS client started you can try to flush the DNS again.

By: daftwill123

daftwill123 — Mon, 06 Apr 2009 02:44:21 +0000

Thanks for the advice. I’ve ran anti-virus many many times, cleared out the system over and over of both spyware and virus and still having trouble. It might be so deep into the system though my protection programs aren’t picking them up. I’m using the latest versions of AVG Free (AVG and Spyware search and destroy.

By: chua

chua — Fri, 03 Apr 2009 00:51:17 +0000

Hi daftwill123, i suspect your PC was infected by virus.
Do a full system scan with your anti virus.

Here’s a free antivirus
http://www.techiecorner.com/102/avast-anti-virus-free-anti-virus-software/
http://www.techiecorner.com/166/avast-how-to-schedule-boot-time-scan-before-window-start/

By: daftwill123

daftwill123 — Fri, 03 Apr 2009 00:48:09 +0000

I’ve get the same error message as Dad:

C:\WINDOWS\Dad>ipconfig/flushdns

Windows IP Configuration

Could not flush the DNS Resolver Cache: Function failed during execution.

C:\WINDOWS\

I tried what Kyle said and it pretty much changed nothing. Though he said something about Windows Vista and both me and Dad are on XP. I’m trying to do this to see if it will let me re-connect to google because I can’t connect to google and so far only google. If any of you got suggestions on that too, to help me re-connect, that’d be awesome.