[Samba] Dynamic DNS updates not working with BIND DLZ
Stephen Jones
A while ago I setup Samba4 on CentOS 6. Samba version was 4.0.0 using
the RPM from SOGo. I used the DLZ BIND backend with BIND 9.8.
I tested with a Windows 7 VM client. When I joined the client to the
domain it was automatically added to the AD DNS and appeared in the
Windows DNS Manager. The VM had a static IP, but if I changed the IP
address that change was automatically reflected in the DNS entry.
I am now adding new real clients to the domain and find that they are
not added to the AD domain DNS. The client has a dynamic IP, but I have
tried changing to a fixed IP address and it makes no difference.
The only changes I can recall between the initial setup and now are:
1. Samba upgrade to 4.0.1. After upgrading I followed the procedure and
ran
samba-tool dbcheck --cross-ncs --fix
samba-tool ntacl sysvolreset
The upgrade changed the permissions of /var/lib/samba4/private back to
root:root 700, which is no good, so I changed back to root:named 750.
I also added "server services = -dns" to smb.conf as per the
instructions because internal DNS is now default.
2. Tested OpenChange. But, prior to doing anything I backed up entire
/var/lib/samba4 directory. When I removed OpenChange (as it is just not
stable yet) I removed /var/lib/samba4 and replaced it with the backup.
So this should not have any effect.
I have checked everything against my notes made when installing Samba4
and can't find anything wrong. In terms of DNS, /etc/named.conf
contains
include "/var/lib/samba4/private/named.conf";
which loads the DLZ module for BIND 9.8.
The /etc/named.conf also has in the options
tkey-gssapi-keytab "/var/lib/samba4/private/dns.keytab";
Permissions of files:
/var/lib/samba4/private/named.conf root:named 640
/var/lib/samba4/private/dns.keytab root:named 640
/var/lib/samba4/private/dns/ root:named 770
It all seems OK (I think), but no dynamic DNS updates. There is nothing
in the samba.log file to suggest a problem. The system log has messages
client <IP address>: update 'example.local/IN' denied
samba_dlz: cancelling transaction on zone example.local
Is there something I need to set in smb.conf? I see there are new
options like "allow dns updates" and "dns update command", which I do
not have specifically set, but I don't know if these only apply to Samba
internal DNS. There is still really no documentation about smb.conf for
Samba4.
Can someone please explain what might be wrong or what I should look
for.
Regards,
Stephen Jones
--
Stephen Jones
lloyds...@fastmail.com.au
--
To unsubscribe from this list go to the following URL and read the
instructions: https://lists.samba.org/mailman/options/samba
Thomas Simmons
I have been experiencing the same problem for the past month or so.
Unfortunately, I have been unable to find a solution. I was able to dig
back through my logs and found that the last DNS update occurred very early
in the morning, so for some reason it just stopped updating. You can start
bind in debugging mode "named -u named -g -d 5", then run "ipconfig
/registerdns" on the Windows client. If you see the following, then you are
experiencing the same issue:
28-Mar-2013 08:26:15.759 failed gss_inquire_cred: GSSAPI error: Major
= Unspecified GSS failure. Minor code may provide more information,
Minor = Success.
28-Mar-2013 08:26:15.760 failed gss_accept_sec_context: GSSAPI error:
Major = Unspecified GSS failure. Minor code may provide more
information, Minor = .
28-Mar-2013 08:26:15.760 process_gsstkey(): dns_tsigerror_badkey
This is not a problem with the internal DNS server, so that may be a
solution. Do be advised that MX and CNAME records are broken in the
internal DNS server, so that may not work for you. I'm working on migrating
everything to Windows Server in my test environment. Since there is no way
to go back to Samba 3, that seems to be the only option I have. Please let
me know if you see the same errors with named in debugging mode. Perhaps
it's a different problem altogether.
Stephen Jones
Thanks for the information. I did as you suggested and ran named in
debug mode and issued 'ipconfig /registerdns' from the client. The
output was similar to your post:
failed gss_inquire_cred: GSSAPI error: Major = Unspecified GSS
failure. Minor code may provide more information, Minor = Success.
process_gsstkey(): dns_tsigerror_noerror
Looks like the server does not believe the client update request is
signed appropriately. Strange, since I know Kerberos is setup fine and
works. I can use nsupdate with Kerberos to edit the AD domain from the
command line. Run 'kinit Admini...@EXAMPLE.LOCAL' gets a ticket,
then 'nsupdate -g' and I can add/remove DNS entries.
I know dynamic updates from the client worked before when I first setup
Samba4. I don't know at what point it decided to stop working. The
only thing I have done that I consider may have influence is upgrading
Samba to 4.0.1.
I don't really want to use the Samba internal DNS. The server runs an
external domain as well as the internal AD domain with a split DNS
setup, and I may not be able to run BIND and Samba DNS together. And
if MX and CNAME in the Samba DNS is broken then it's no good to me
running a mail server. The BIND DLZ seems a much better option to me.
I certainly hope there is a fix for this problem.
Regards,
Stephen Jones
References
1. mailto:lloyds...@fastmail.com.au
2. https://lists.samba.org/mailman/options/samba
Stephen Jones
Thanks for the suggestion but, unfortunately, it's not that. I am
aware of the kerberos sensitivity to time differences. When I
installed Samba4 I built a custom ntp rpm as the version shipped with
RHEL/CentOS does not support signed ntp. I tested this by shifting the
clock on the client and it worked its way back again.
Out of interest I decided to try this again, some months after the
initial install. My laptop's clock was about 10 sec off the DC. I
changed it to 2 min, and it stays there. Running 'w32tm /resync
/rediscover' just reports "no time data was available".
So I actually have 2 problems. Dynamic dns updates, that DID work
before, now do not, and ntp updates, that DID work before, now also do
not. Nothing has changed on the server with dns or ntp configuration.
There is only the upgrade of Samba from 4.0.0 to 4.0.1.
It would seem that there is some problem with kerberos that the signed
requests fail. Yet I can use kinit to authenticate and get a valid
ticket. Kerberos is buried inside Samba so I have no idea what is
wrong with it and why, nor do I have any idea how to fix it.
I have trawled the web for hours on this. I read plenty of similar
problems, but no solutions other than the obvious stuff I already
checked. It's really very frustrating.
Regards,
Stephen Jones
On Tue, Apr 23, 2013, at 01:30 AM, ?icro MEGAS wrote:
Hey there,
had a similar problem in the past and resolved it today. The error
was caused by time mismatch between the host and the client. Did you
check that ntp is working fine and your time between samba4 and
windows host is in sync (<5min) ?
Lucas.
Птн 12 Апр 2013 03:00:41 +0400, Stephen Jones
<lloyds...@fastmail.com.au> написал:
instructions: [2][1]https://lists.samba.org/mailman/options/samba
References
1. mailto:lloyds...@fastmail.com.au
2. [2]https://lists.samba.org/mailman/options/samba
--
To unsubscribe from this list go to the following URL and read the
instructions: [3]https://lists.samba.org/mailman/options/samba
References
1. https://lists.samba.org/mailman/options/samba
2. https://lists.samba.org/mailman/options/samba
3. https://lists.samba.org/mailman/options/samba