[Samba] Replicated Failover Domain Controller and file server using LDAP

[Rowland Penny]

On 27/08/14 12:54, Gary Wright wrote:
> Hi All
>
> thought I'd post my results from following your notes when trying to replicate my Samba PDC onto a Samba BDC as seen here
>
> https://wiki.samba.org/index.php/1.0._Configuring_Samba
>
> everything seemed to work as described until I got into the 'Initialization LDAP Database' and preloading the edited "preload-differentialdesign.ldif" file, kept getting a failure from the
>
> "dn: sambaDomainName= DDESIGN ,ou=Domains,dc= differentialdesign ,dc= org "
>
> section, no matter what options I used.
>
> Looking at my /var/log/messages on both my DC1 & DC2 I could see continual errors trying to access our either of our 2 DNS servers (example below)
>
> Aug 25 16:37:55 dc1 samba[2009]: [2014/08/25 16:37:55.120350, 0] ../lib/util/util_runcmd.c:317(samba_runcmd_io_handler)
> Aug 25 16:37:55 dc1 samba[2009]: /usr/local/samba/sbin/samba_dnsupdate: 25-Aug-2014 16:37:55.120 dispatch 0x7f3734031db0: shutting down due to TCP receive error: 10.5.31.11#53: connection reset
> Aug 25 16:37:55 dc1 samba[2009]: [2014/08/25 16:37:55.120519, 0] ../lib/util/util_runcmd.c:317(samba_runcmd_io_handler)
> Aug 25 16:37:55 dc1 samba[2009]: /usr/local/samba/sbin/samba_dnsupdate: ; Communication with 10.5.31.11#53 failed: unexpected error
>
> though both DNS servers were accessible and resolving addresses perfectly normally.
>
> I started to troubleshoot the samba status more closely and came across the 'samba_dnsupdate --verbose' command. This gave me a detailed list failures/successes trying to access DNS server records from both DC's
>
> [root at dc1 ~]# samba_dnsupdate --verbose
> IPs: ['10.5.15.11']
> Looking for DNS entry A tmxatrium.lan 10.5.15.11 as tmxatrium.lan.
> Looking for DNS entry A dc1.tmxatrium.lan 10.5.15.11 as dc1.tmxatrium.lan.
> Looking for DNS entry A gc._msdcs.tmxatrium.lan 10.5.15.11 as gc._msdcs.tmxatrium.lan.
> Failed to find matching DNS entry A gc._msdcs.tmxatrium.lan 10.5.15.11 as gc._msdcs.tmxatrium.lan
> Looking for DNS entry CNAME 7e32e874-8f2b-459f-b54f-bc96162e4afb._msdcs.tmxatrium.lan dc1.tmxatrium.lan as 7e32e874-8f2b-459f-b54f-bc96162e4afb._msdcs.tmxatrium.lan.
> Failed to find DNS entry CNAME 7e32e874-8f2b-459f-b54f-bc96162e4afb._msdcs.tmxatrium.lan dc1.tmxatrium.lan
> etc
> etc
>
>
> I then simply created the DNS records for each of the failures then restarted SAMBA on my BDC, et voila my account information replicated perfectly.
>
> I'm clearly not using LDAP but I'm not sure I actually need to ?? Is there any advantage ??
>
>
> Regards
>
> Gary
>
> 		
>
> Gary Wright
>
>
> System Administrator
>
>
> 7th floor, Becket House, 36 Old Jewry
>
> London, UK, EC2R 8DD
>
>
>
>
>
> ✉ gary.wright @tmxatrium.com
>
>
> Office: +44 203 194 2536
> Mobile: +44 7823 773 262
>
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>
Hi, I 'think' that I can see your problem here, you are obviously using 
samba 4.1.x and you are following a howto last updated approx 7 years 
ago. You have set samba as an NT4-style domain controller, which is ok, 
but you are now trying to use tools that are meant to be used with the 
dns server built into samba4, I do not think they will work with your 
setup, is there any reason that you do not want to use an AD DC domain??

Rowland