Assuming you have rndc configured properly for remote management of all these servers, it's simply:
rndc -s server1 flush rndc -s server2 flush rndc -s server3 flush etc... script however you'd like to achieve in your environment. -Vinny From: bind-users-boun...@lists.isc.org [mailto:bind-users-boun...@lists.isc.org] On Behalf Of Mohammed Shareef Sent: Monday, December 07, 2015 4:42 AM To: bind-users@lists.isc.org Subject: FW: SV: Bind bind high recv-q Hi All, I have 140 windows dns server on which we have install ISC bind services, I would like to know any script to flush the dns in all cache. Thanks & Regards, Mohammed Shareef > From: s...@stofa.dk<mailto:s...@stofa.dk> > To: d...@dotat.at<mailto:d...@dotat.at> > Subject: SV: Bind bind high recv-q > Date: Sun, 6 Dec 2015 19:58:38 +0000 > CC: bind-users@lists.isc.org<mailto:bind-users@lists.isc.org> > > Hi Tony, > > Nope, my server is not an open resolver, but a lot of clients are using it :) > - Actually one of my customers had a broken netgear device that was making > 1000 qps for time-g.netgear.com. Probably some kind of software bug. > > I can recommend dnstop to find "bad dns clients" - But dnstop also showed me > I'm getting 5-7K qps, and not 700-800 as collectd showed me. > > Do you think this is too much for a VM? - My VM is only loaded 50% on each > core. > > /Søren > > -----Oprindelig meddelelse----- > Fra: Tony Finch [mailto:fa...@hermes.cam.ac.uk] På vegne af Tony Finch > Sendt: 4. december 2015 13:34 > Til: Søren Andersen <s...@stofa.dk<mailto:s...@stofa.dk>> > Cc: bind-users@lists.isc.org<mailto:bind-users@lists.isc.org> > Emne: Re: Bind bind high recv-q > > Søren Andersen <s...@stofa.dk<mailto:s...@stofa.dk>> wrote: > > > > I'm experiencing some strange problems with my bind installation. - I > > notice my bind recv-q is quite high sometimes.. therefore my DNS > > clients can experience DNS lookup to take 1-4 secs. My bind is running > > on a 4 core vm I VMware with 8Gb ram. - At peak I receive app. 700-800 > > QPS. - The load is 20-40% on each CPU core. - I've also configured 2 RPZ > > zones. > > Is your server an open resolver being used as part of a DDoS attack? > > Do you have compromised client machines running malware that hammers your > server? > > Find out where the queries are coming from using netflow or tcpdump or query > logging. > > Tony. > -- > f.anthony.n.finch <d...@dotat.at<mailto:d...@dotat.at>> http://dotat.at/ > Southeast Iceland: Southeasterly 6 to gale 8, becoming cyclonic 7 to severe > gale 9, then veering westerly gale 8 to storm 10, perhaps violent storm 11 > later. High or very high later. Wintry showers. Moderate or poor, > occasionally very poor. > _______________________________________________ > Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe > from this list > > bind-users mailing list > bind-users@lists.isc.org<mailto:bind-users@lists.isc.org> > https://lists.isc.org/mailman/listinfo/bind-users
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