dnscache will not start

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Emma Mujica Alvarez
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Joined: Fri Sep 19, 2014 7:29 am

dnscache will not start

Postby Emma Mujica Alvarez » Wed Sep 24, 2014 1:42 am

At the end, I solve the problem by disabling zimbra-dnscache.



In any case, thanks.


AndrewN
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Joined: Mon Sep 15, 2014 3:27 pm

dnscache will not start

Postby AndrewN » Wed Sep 24, 2014 10:30 am

Where in LDAP is it pulling? unbound.conf just got set back to 8.88.8 instead of 8.8.8.8 again. Now that I know what to fix, it's not a huge problem to fix, but it's still annoying :/
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quanah
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dnscache will not start

Postby quanah » Wed Sep 24, 2014 1:03 pm

Hi,



If you examine the unbound.conf.in file, you will see the following line:



%%explode       forward-addr: VAR:zimbraDNSMasterIP%%


So zimbraDNSMasterIP (which is a multi valued attribute) is what needs updating.  You can look at the current value(s), and then add what you want and remove what you don't want.



For example:



zmprov ms `zmhostname` +zimbraDNSMasterIP  8.8.8.8



would add 8.8.8.8 as a value



zmprov ms `zmhostname` -zimbraDNSMasterIP 8.8.8



Would remove 8.8.8 as a value

--
Quanah Gibson-Mount
Product Architect, Symas http://www.symas.com/
OpenLDAP Core team http://www.openldap.org/project/
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dbayer
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dnscache will not start

Postby dbayer » Wed Jan 21, 2015 12:00 pm

This was exactly what I needed to solve my issue. I had added some outside DNS Servers, and Zimbra was round robining them when it was looking for it's internal postfix server name. Naturally this was failing, every time it switched to the outside DNS servers. By following your advice above I was able to remove the outside DNS servers, and now everything works great!
metux
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dnscache will not start

Postby metux » Wed Feb 04, 2015 4:44 pm

The correct solution is to drop that useless dns-proxy and use a real nameserver (eg. bind9 or djbdns).

Actually, I really wonder why a mailserver like Zimbra ships it's own nameserver, which is completely out of scope - totally redundant.



Oh, by the way: are you sure, you want to send all your DNS traffic to google ?!
Gram
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Re: dnscache will not start

Postby Gram » Wed Sep 25, 2019 3:03 am

quanah wrote:zmprov ms `zmhostname` +zimbraDNSMasterIP  8.8.8.8

would add 8.8.8.8 as a value

zmprov ms `zmhostname` -zimbraDNSMasterIP 8.8.8

Would remove 8.8.8 as a value


This worked for me too, thanks!

I just migrated to Ubuntu 18.04 and ran into problems with Unbound forwarding to systemd-resolved forwarding to external Bind. In my case I needed to $ zmprov ms `zmhostname` -zimbraDNSMasterIP 127.0.0.53 before adding my external local DNS server.

$ nslookup google.com 127.0.0.53 would succeed using systemd-resolved (forwarding to external Bind), but $ nslookup google.com 127.0.0.1 would fail using Unbound (automatically configured to forward to 127.0.0.53 during install). My guess is systemd-resolved either doesn't support, or isn't configured for, recursion. The Zimbra installer automatically chose 127.0.0.53 during installation. I was using a DHCP reservation during the install, but I'm not sure if a static address would have changed this behavior.

metux wrote:The correct solution is to drop that useless dns-proxy and use a real nameserver (eg. bind9 or djbdns).

Actually, I really wonder why a mailserver like Zimbra ships it's own nameserver, which is completely out of scope - totally redundant.


I thought the same thing at first. Just now, when I was having name resolution issues during this migration, I noticed in /var/log/zimbra.log that locally generated Zimbra alerts could not be delivered because my MX record couldn't be resolved. In the past, before I started using Zimbra's dnscache, I noticed similar errors if my external DNS server was unavailable. Zimbra's dnscache helps improve reliability, at least a little bit, for me.

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