[Samba] Workaround for bind9 reload bug : samba_dlz Ignoring duplicate zone

[L.P.H. van Belle]

> -----Oorspronkelijk bericht-----
> Van: samba [mailto:samba-bounces at lists.samba.org] Namens 
> Prunk Dump via samba
> Verzonden: dinsdag 13 maart 2018 11:51
> Aan: samba at lists.samba.org
> Onderwerp: Re: [Samba] Workaround for bind9 reload bug : 
> samba_dlz Ignoring duplicate zone
> 
> Hi Samba Team !
> 
> First thank you all for your help !
> 
> Here some clarification on the problem.
> 
> -> The problem affect only my reverse zone "16.172.in-addr.arpa"
> created with Samba. After the install, the zone contain only the PDC
> reverse entry. So when bind9 in reloaded or reconfigured the "nslookup
> 172.16.0.30" command fail. When bind9 is restarted it works.
> 
> -> Here the bind9 logs. We see a "rndc reconfig" command that make
> bind9 fail. (Full log in attachment).
> 
> -------------------
> starting BIND 9.10.3-P4-Debian <id:ebd72b3> -f -u bind
> ...
> Loading 'AD DNS Zone' using driver dlopen
> samba_dlz: started for DN 
> DC=lan,DC=lyc-guillaume-fichet,DC=ac-grenoble,DC=fr
> samba_dlz: starting configure
> samba_dlz: configured writeable zone 
> 'lan.lyc-guillaume-fichet.ac-grenoble.fr'
> samba_dlz: configured writeable zone '16.172.in-addr.arpa'
> samba_dlz: configured writeable zone
> '_msdcs.lan.lyc-guillaume-fichet.ac-grenoble.fr'
> automatic empty zone: 10.IN-ADDR.ARPA
> ...
> all zones loaded
> running
> received control channel command 'reconfig'
> ...
> Loading 'AD DNS Zone' using driver dlopen
> samba_dlz: starting configure
> samba_dlz: Ignoring duplicate zone
> 'lan.lyc-guillaume-fichet.ac-grenoble.fr' from
> 'DC=@,DC=lan.lyc-guillaume-fichet.ac-grenoble.fr,CN=MicrosoftD
NS,DC=DomainDnsZones,DC=lan,DC=lyc-guillaume-fichet,DC=ac-> grenoble,DC=fr'
> samba_dlz: Ignoring duplicate zone '16.172.in-addr.arpa' from
> 'DC=@,DC=16.172.in-addr.arpa,CN=MicrosoftDNS,DC=DomainDnsZones
,DC=lan,DC=lyc-guillaume-fichet,DC=ac-grenoble,DC=fr'
> samba_dlz: Ignoring duplicate zone
> '_msdcs.lan.lyc-guillaume-fichet.ac-grenoble.fr' from
> 'DC=@,DC=_msdcs.lan.lyc-guillaume-fichet.ac-grenoble.fr,CN=Mic
rosoftDNS,DC=ForestDnsZones,DC=lan,DC=lyc-guillaume-fichet,DC=ac-> grenoble,DC=fr'
> automatic empty zone: 10.IN-ADDR.ARPA
> ...
> zone 16.172.in-addr.arpa/NONE: (other) removed
> ...
> zone lan.lyc-guillaume-fichet.ac-grenoble.fr/NONE: (other) removed
> zone _msdcs.lan.lyc-guillaume-fichet.ac-grenoble.fr/NONE: 
> (other) removed
> reloading configuration succeeded
> any newly configured zones are now loaded
> samba_dlz: shutting down
> -------------------
> 
> -> Using some wrapper script, I have found that this is systemd that
> send the "rndc reconfig" command. But impossible to find in witch
> script ( this is not systemd-networkd that is not started ).
> 
> --------------------
> root at fichdc01:~# grep -r 'reconfig' /etc/init.d/
> /etc/init.d/isc-dhcp-server:        echo "Run 'dpkg-reconfigure
> isc-dhcp-server' to fix the problem."
> root at fichdc01:~# grep -r 'reconfig' /lib/systemd/
> Fichier binaire /lib/systemd/systemd-networkd correspondant
> --------------------
> 
> -> Adding the "empty-zones-enable no;" option make the zone working !
> But I still have the same logs in bind9. And the "samba_dlz: shutting
> down" line ! I don't know if bind9 will work correctly.
> 
> --------------------
> received control channel command 'reconfig'
> ...
> Loading 'AD DNS Zone' using driver dlopen
> samba_dlz: starting configure
> samba_dlz: Ignoring duplicate zone
> 'lan.lyc-guillaume-fichet.ac-grenoble.fr' from
> 'DC=@,DC=lan.lyc-guillaume-fichet.ac-grenoble.fr,CN=Micr...
> samba_dlz: Ignoring duplicate zone '16.172.in-addr.arpa' from
> 'DC=@,DC=16.172.in-addr.arpa,CN=MicrosoftDNS,DC=DomainDnsZones
,DC=lan,DC=lyc..
> samba_dlz: Ignoring duplicate zone
> '_msdcs.lan.lyc-guillaume-fichet.ac-grenoble.fr' from
> 'DC=@,DC=_msdcs.lan.lyc-guillaume-fichet.ac-greno..
> ...
> Mar 13 11:23:49 fichdc01 named[463]: zone 16.172.in-addr.arpa/NONE:
> (other) removed
> Mar 13 11:23:49 fichdc01 named[463]: zone
> lan.lyc-guillaume-fichet.ac-grenoble.fr/NONE: (other) removed
> Mar 13 11:23:49 fichdc01 named[463]: zone
> _msdcs.lan.lyc-guillaume-fichet.ac-grenoble.fr/NONE: (other) removed
> Mar 13 11:23:49 fichdc01 named[463]: reloading configuration succeeded
> Mar 13 11:23:49 fichdc01 named[463]: any newly configured 
> zones are now loaded
> Mar 13 11:23:49 fichdc01 named[463]: samba_dlz: shutting down
> --------------------
> 
> Thank again !
> 
> Baptiste.
> -- 
> To unsubscribe from this list go to the following URL and read the
> instructions:  https://lists.samba.org/mailman/options/samba
> 
> 


Ok, as far i know, only 2 point with reload commands. ( and rndc thaw also does a reload )

rgrep rndc /lib/systemd/* | grep reload
/lib/systemd/system/bind9-pkcs11.service:ExecReload=/usr/sbin/rndc reload
/lib/systemd/system/bind9.service:ExecReload=/usr/sbin/rndc reload


rgrep rndc /etc/* | grep reload
/etc/init.d/bind9:   /usr/sbin/rndc reload >/dev/null && log_end_msg 0 || log_end_msg   

You already changed the systemd settings you could change the init script also. 
Just copy past the restart part into the reload part. 


Are you using dhcp also on the dc's ? 
ddns update might be a cause here.


Greetz, 

Louis