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<p>Including unbound users.</p>
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<div class="ecxmoz-signature">-- <br>
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<font color="#3366ff"><font color="#000000">Respectfully<b><br>
</b><b>Mahdi A. Mahdi</b></font></font><font color="#3366ff"><br>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Mahdi Adnan <mahdi.adnan@outlook.com><br>
<b>Sent:</b> Thursday, July 6, 2017 10:49 AM<br>
<b>To:</b> W.C.A. Wijngaards<br>
<b>Subject:</b> Re: Unbound Srvfail cache</font>
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<p>Hi <span style="font-size:12pt">Wouter,</span></p>
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<p>The issue does scale for more than 15 minutes, and it will keeps on this behavior unless i restart the service or flush the cache.</p>
<p>Version 1.4.20 is the latest from redhat.</p>
<p>I configured <span>infra-host-ttl to 120 seconds, will see if this helps.</span></p>
<p><span> </span> </p>
<p>Thanks you very much.</p>
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<div class="x_ecxmoz-signature">-- <br>
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<font color="#3366ff"><font color="#000000">Respectfully<b><br>
</b><b>Mahdi A. Mahdi</b></font></font><font color="#3366ff"><br>
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<div id="x_divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Unbound-users <unbound-users-bounces@unbound.net> on behalf of W.C.A. Wijngaards via Unbound-users <unbound-users@unbound.net><br>
<b>Sent:</b> Thursday, July 6, 2017 10:23:06 AM<br>
<b>To:</b> unbound-users@unbound.net<br>
<b>Subject:</b> Re: Unbound Srvfail cache</font>
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<div class="PlainText">Hi Mahdi,<br>
<br>
Unbound only probes every 15 minutes (infra-ttl) to see if servers are<br>
back up. You could lower infra-ttl in your config.<br>
<br>
Also, you could update, 1.4.20 is from 2012. Perhaps the newer version<br>
does not have this issue in this manner.<br>
<br>
You can also flush the infra cache, with unbound-control flush_infra<br>
all, that way you don't lose the DNS cache.<br>
<br>
Best regards, Wouter<br>
<br>
On 06/07/17 08:05, Mahdi Adnan via Unbound-users wrote:<br>
> Hi folks,<br>
> <br>
> <br>
> We have a situation here with Unbound, during internet outage for an<br>
> hour or so, Unbound keeps replying with server servfail for valid<br>
> domains even after it gain access to internet, to fix this, i have to<br>
> reload or restart Unbound.<br>
> <br>
> This happens every time we lose internet for more than 30 minutes or so.<br>
> <br>
> Any way to fix this ?<br>
> <br>
> Appreciate your time.<br>
> <br>
> <br>
> OS: CentOS 7.3<br>
> <br>
> Unbound: Version 1.4.20<br>
> <br>
> <br>
> Config:<br>
> <br>
> <br>
> server:<br>
> <br>
> access-control: 0.0.0.0/0 deny<br>
> access-control: x.x.x.x/x allow<br>
> verbosity: 1<br>
> statistics-interval: 0<br>
> statistics-cumulative: no<br>
> extended-statistics: yes<br>
> num-threads: 16<br>
> interface: xx.xx.xx.xx<br>
> interface: xx.xx.xx.xx<br>
> interface: xx.xx.xx.xx<br>
> interface: xx.xx.xx.xx<br>
> interface: 127.0.0.1<br>
> interface-automatic: no<br>
> port: 53<br>
> outgoing-range: 8196<br>
> num-queries-per-thread: 1600<br>
> outgoing-num-tcp: 100<br>
> incoming-num-tcp: 100<br>
> so-rcvbuf: 8m<br>
> so-sndbuf: 8m<br>
> msg-cache-size: 2G<br>
> rrset-cache-size: 4G<br>
> msg-cache-slabs: 16<br>
> rrset-cache-slabs: 16<br>
> infra-cache-slabs: 16<br>
> infra-cache-numhosts: 10000000<br>
> do-ip4: yes<br>
> do-ip6: yes<br>
> do-udp: yes<br>
> do-tcp: yes<br>
> do-daemonize: yes<br>
> chroot: ""<br>
> username: "unbound"<br>
> directory: "/etc/unbound"<br>
> logfile: "/var/log/unbound.log"<br>
> log-queries: no<br>
> use-syslog: yes<br>
> log-time-ascii: yes<br>
> pidfile: "/var/run/unbound/unbound.pid"<br>
> root-hints: "/etc/unbound/root.hints"<br>
> hide-identity: yes<br>
> hide-version: yes<br>
> harden-glue: yes<br>
> harden-dnssec-stripped: yes<br>
> harden-below-nxdomain: yes<br>
> harden-referral-path: yes<br>
> use-caps-for-id: no<br>
> unwanted-reply-threshold: 100000<br>
> prefetch: yes<br>
> prefetch-key: yes<br>
> rrset-roundrobin: yes<br>
> minimal-responses: yes<br>
> trusted-keys-file: /etc/unbound/keys.d/*.key<br>
> auto-trust-anchor-file: "/var/lib/unbound/root.key"<br>
> val-log-level: 1<br>
> key-cache-size: 1G<br>
> key-cache-slabs: 16<br>
> neg-cache-size: 1k<br>
> include: /etc/unbound/local.d/*.conf<br>
> # Remote control config section.<br>
> remote-control:<br>
> control-enable: yes<br>
> # control-interface: 127.0.0.1<br>
> # control-port: 953<br>
> server-key-file: "/etc/unbound/unbound_server.key"<br>
> server-cert-file: "/etc/unbound/unbound_server.pem"<br>
> control-key-file: "/etc/unbound/unbound_control.key"<br>
> control-cert-file: "/etc/unbound/unbound_control.pem"<br>
> # Stub and Forward zones<br>
> include: /etc/unbound/conf.d/*.conf<br>
> <br>
> <br>
> <br>
> -- <br>
> <br>
> Respectfully*<br>
> **Mahdi A. Mahdi*<br>
> <br>
<br>
<br>
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