Bug 15891 - Figuring out the DC name from IP address fails and breaks fork_domain_child()
Summary: Figuring out the DC name from IP address fails and breaks fork_domain_child()
Status: RESOLVED FIXED
Alias: None
Product: Samba 4.1 and newer
Classification: Unclassified
Component: Winbind (show other bugs)
Version: 4.19.4
Hardware: All All
: P5 normal (vote)
Target Milestone: ---
Assignee: Jule Anger
QA Contact: Samba QA Contact
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-07-31 12:23 UTC by Pavel Filipenský
Modified: 2025-09-09 15:40 UTC (History)
2 users (show)

See Also:

Attachments
patch for 4.22 and 4.21 (6.07 KB, patch)
2025-08-06 08:09 UTC, Andreas Schneider 		ab: review+
Details
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Description Pavel Filipenský 2025-07-31 12:23:05 UTC 
Environment:
Samba serving as IPA domain controller, providing forest trust to Active Directory
is having issues.

Child winbind during startup tries to figure out the DC name. It is using function dcip_check_name() that either uses CLDAP or NETBIOS to resolve the IP to hostname. However if SERVER ROLE = IPA DOMAIN CONTROLLER, only NETBIOS is tried.

It looks that Windows server no longer provide netbios and the winbind child for the domain is not able to start at all.

smb.conf has:

security = USER
server role = IPA domain controller


Fix will follow.
Comment 1 Samba QA Contact 2025-08-05 14:52:02 UTC 
This bug was referenced in samba master:

4921c3304e5e0480e5bb80a757b3f04b3b92c3b1
d88268102ade07fab345e04109818d97d8843a14
1dbafcc4e4ff8f39af5ca737b30e9821413dd1f2
a4dff82e45308db3ccabac2a55c03d52f04d7b4d
Comment 2 Andreas Schneider 2025-08-06 08:09:53 UTC 
Created attachment 18682 [details]
patch for 4.22 and 4.21
Comment 3 Alexander Bokovoy 2025-08-06 08:11:18 UTC 
Comment on attachment 18682 [details]
patch for 4.22 and 4.21

LGTM
Comment 4 Andreas Schneider 2025-08-06 09:45:10 UTC 
Jule, please apply the patches to the corresponding branches. Thanks!
Comment 5 Jule Anger 2025-08-06 11:45:39 UTC 
Pushed to autobuild-v4-{22,21}-test.
Comment 6 Samba QA Contact 2025-08-06 13:08:02 UTC 
This bug was referenced in samba v4-21-test:

a8e2ea60831fca3e5dc6efea3520cea60bffdf9a
1c6b6494735920ec01d1b252a3c8b9b7835c0c80
7bf2051aadd45562d5e99b10b9eced96cb9592e3
2a52c97607031dab1dd9a14a9a057db99ea582b8
Comment 7 Samba QA Contact 2025-08-11 07:54:12 UTC 
This bug was referenced in samba v4-22-test:

fe8eafc289dfbb6f2b6c706f2a8a68186807d4f8
d14fa6eb96a9f296d386ff4864e4f016440f2ac8
00adb3104e745babb2c330fa9c9e324805395edb
3364797676624aa9367076a69b2daf73870429ba
Comment 8 Jule Anger 2025-08-11 11:16:47 UTC 
Closing out bug report.

Thanks!
Comment 9 Samba QA Contact 2025-08-21 15:26:04 UTC 
This bug was referenced in samba v4-22-stable (Release samba-4.22.4):

fe8eafc289dfbb6f2b6c706f2a8a68186807d4f8
d14fa6eb96a9f296d386ff4864e4f016440f2ac8
00adb3104e745babb2c330fa9c9e324805395edb
3364797676624aa9367076a69b2daf73870429ba
Comment 10 Samba QA Contact 2025-09-09 15:40:57 UTC 
This bug was referenced in samba v4-21-stable (Release samba-4.21.8):

a8e2ea60831fca3e5dc6efea3520cea60bffdf9a
1c6b6494735920ec01d1b252a3c8b9b7835c0c80
7bf2051aadd45562d5e99b10b9eced96cb9592e3
2a52c97607031dab1dd9a14a9a057db99ea582b8