[Samba] samba 4.4.5 DC with bind9: DNS update failing with NOTAUTH
Achim Gottinger
achim at ag-web.biz
Mon Jul 18 21:44:32 UTC 2016
Am 18.07.2016 um 23:31 schrieb Norbert Hanke:
> On 18.07.2016 22:48, Achim Gottinger wrote:
>>
>>
>> Am 18.07.2016 um 11:45 schrieb Norbert Hanke:
>>> On 18.07.2016 01:52, Achim Gottinger wrote:
>>>>
>>>>
>>>> Am 18.07.2016 um 01:02 schrieb Norbert Hanke:
>>>>> Hello,
>>>>>
>>>>> I'm trying to join a samba 4 DC to an already existing samba 4 DC,
>>>>> both with BIND9_DLZ. Samba is at version 4.4.5, bind is version
>>>>> 9.10.4-P1, all brand new.
>>>>>
>>>>> The existing DC runs fine, but the added DC refuses to update its
>>>>> local bind database: every attempt to update the local DNS results
>>>>> in "update failed: NOTAUTH". AD replication works perfectly.
>>>>>
>>>>> Both systems are set up identically except for the
>>>>> provisioning/joining command. On the first I did
>>>>> samba-tool domain provision --use-rfc2307 --domain=$domain
>>>>> --server-role=dc --dns-backend=BIND9_DLZ \
>>>>> --realm=$realm --adminpass=Wonttell
>>>>> and on the second I do
>>>>> samba-tool domain join $domain DC -Uadministrator --realm=$realm
>>>>> --dns-backend=BIND9_DLZ
>>>>>
>>>>> Versions are the same, bind config is the same, I tried follow
>>>>> every rule I could find.
>>>>>
>>>>> # samba_dnsupdate --verbose -d 9
>>>>> INFO: Current debug levels:
>>>>> all: 9
>>>>> (... more such levels ...)
>>>>> lpcfg_load: refreshing parameters from /usr/local/samba/etc/smb.conf
>>>>> Processing section "[global]"
>>>>> Processing section "[netlogon]"
>>>>> Processing section "[sysvol]"
>>>>> pm_process() returned Yes
>>>>> added interface eth0 ip=192.168.1.9 bcast=192.168.1.255
>>>>> netmask=255.255.255.0
>>>>> IPs: ['192.168.1.9']
>>>>> Module 'tombstone_reanimate' is disabled. Skip
>>>>> registration.lpcfg_servicenumber: couldn't find ldb
>>>>> schema_fsmo_init: we are master[no] updates allowed[no]
>>>>> schema_fsmo_init: we are master[no] updates allowed[no]
>>>>> Looking for DNS entry A dc2.ad.domain.ch 192.168.1.9 as
>>>>> dc2.ad.domain.ch.
>>>>> Looking for DNS entry A ad.domain.ch 192.168.1.9 as ad.domain.ch.
>>>>> Failed to find matching DNS entry A ad.domain.ch 192.168.1.9
>>>>> need update: A ad.domain.ch 192.168.1.9
>>>>> (... many more such Looking...need update blocks)
>>>>> 24 DNS updates and 0 DNS deletes needed
>>>>> ldb_wrap open of secrets.ldb
>>>>> Received smb_krb5 packet of length 298
>>>>> Received smb_krb5 packet of length 1311
>>>>> update(nsupdate): A ad.domain.tld 192.168.1.9
>>>>> Calling nsupdate for A ad.domain.tld 192.168.1.9 (add)
>>>>> Outgoing update query:
>>>>> ;; ->>HEADER<<- opcode: UPDATE, status: NOERROR, id: 0
>>>>> ;; flags:; ZONE: 0, PREREQ: 0, UPDATE: 0, ADDITIONAL: 0
>>>>> ;; UPDATE SECTION:
>>>>> ad.domain.tld. 900 IN A 192.168.1.9
>>>>>
>>>>> update failed: NOTAUTH
>>>>> Failed nsupdate: 2
>>>>> (... many more such failed updates ...)
>>>>> Failed update of 24 entries
>>>>> # 22:37:30 root at dc2:/root/
>>>>>
>>>>>
>>>>> In /var/log/syslog there are these equivalent 24 error message
>>>>> every 10 minutes:
>>>>> Jul 17 22:52:06 dc2 samba[3960]: [2016/07/17 22:52:06.742592, 0]
>>>>> ../lib/util/util_runcmd.c:328(samba_runcmd_io_handler)
>>>>> Jul 17 22:52:06 dc2 samba[3960]:
>>>>> /usr/local/samba/sbin/samba_dnsupdate: update failed: NOTAUTH
>>>>> and the last of the 24 entries is always followed by
>>>>> Jul 17 22:52:06 dc2 samba[3960]: [2016/07/17 22:52:06.866877, 0]
>>>>> ../source4/dsdb/dns/dns_update.c:295(dnsupdate_nameupdate_done)
>>>>> Jul 17 22:52:06 dc2 samba[3960]:
>>>>> ../source4/dsdb/dns/dns_update.c:295: Failed DNS update -
>>>>> NT_STATUS_TOO_MANY_OPENED_FILES
>>>>>
>>>>> smb.conf is minimalistic:
>>>>>
>>>>> # Global parameters
>>>>> [global]
>>>>> netbios name = DC2
>>>>> realm = AD.DOMAIN.TLD
>>>>> server services = s3fs, rpc, nbt, wrepl, ldap, cldap, kdc,
>>>>> drepl, winbindd, ntp_signd, kcc, dnsupdate
>>>>> workgroup = DOMAIN
>>>>> server role = active directory domain controller
>>>>>
>>>>> [netlogon]
>>>>> path =
>>>>> /usr/local/samba/var/locks/sysvol/ad.domain.tld/scripts
>>>>> read only = No
>>>>>
>>>>> [sysvol]
>>>>> path = /usr/local/samba/var/locks/sysvol
>>>>> read only = No
>>>>>
>>>>> Maybe somebody has an idea what I did wrong?
>>>>>
>>>>>
>>>>>
>>>> resolv.conf on dc2 should point to dc1 during join. Is that the case?
>>>> Does kinit work on dc2?
>>>>
>>>>
>>> Yes, I did
>>> cat <<EOF >/etc/resolv.conf
>>> domain $domain
>>> nameserver $otherip
>>> nameserver $ip
>>> EOF
>>>
>>> ($ip is the local system, $otherip is the existing DC)
>>>
>>> resulting in
>>>
>>> # cat /etc/resolv.conf
>>> domain ad.domain.ch
>>> nameserver 192.168.1.8
>>> nameserver 192.168.1.9
>>>
>>>
>>> Before joining I did
>>>
>>> klist -e | grep administrator@$realm || kinit administrator
>>>
>>> and looking at it right now half a day later I get
>>>
>>> # klist -e
>>> Ticket cache: FILE:/tmp/krb5cc_0
>>> Default principal: administrator at AD.DOMAIN.CH
>>>
>>> Valid starting Expires Service principal
>>> 17/07/16 21:56:59 18/07/16 07:56:59
>>> krbtgt/AD.DOMAIN.CH at AD.DOMAIN.CH
>>> renew until 18/07/16 21:56:55, Etype (skey, tkt):
>>> aes256-cts-hmac-sha1-96, aes256-cts-hmac-sha1-96
>>>
>>> So it is expired right now, another kinit gets me a new tgt:
>>> # kinit -R
>>> kinit: Ticket expired while renewing credentials
>>> # kinit
>>> Password for administrator at AD.DOMAIN.CH:
>>> Warning: Your password will expire in 32 days on Sat 20 Aug 2016
>>> 08:27:10 UTC
>>> # klist -e
>>> Ticket cache: FILE:/tmp/krb5cc_0
>>> Default principal: administrator at AD.DOMAIN.CH
>>>
>>> Valid starting Expires Service principal
>>> 18/07/16 09:35:01 18/07/16 19:35:01
>>> krbtgt/AD.DOMAIN.CH at AD.DOMAIN.CH
>>> renew until 19/07/16 09:34:58, Etype (skey, tkt):
>>> aes256-cts-hmac-sha1-96, aes256-cts-hmac-sha1-96
>>> samba_dnsupdate still fails.
>>>
>> You can try to run
>>
>> root at dc2:~# samba_upgradedns --dns-backend=BIND9_DLZ
>>
>> and verify that bind has read rights on the dns.keytab
>>
>> root at dc2:~# ls -l /var/lib/samba/private/dns.keytab
>> -rw-r----- 1 root bind 732 Jun 28 16:08
>> /var/lib/samba/private/dns.keytab
>>
>> Also check that the keytab contains such keys.
>>
>> root at dc2:~# klist -Kek /var/lib/samba/private/dns.keytab
>> Keytab name: FILE:/var/lib/samba/private/dns.keytab
>> KVNO Principal
>> ----
>> --------------------------------------------------------------------------
>> 1 DNS/dc2.domain.local at DOMAIN.LOCAL (des-cbc-crc) (...)
>> 1 dns-dc2 at DOMAIN.LOCAL (des-cbc-crc) (...)
>> 1 DNS/dc2.domain.local at DOMAIN.LOCAL (des-cbc-md5) (...)
>> 1 dns-dc2 at DOMAIN.LOCAL (des-cbc-md5) (...)
>> 1 DNS/dc2.domain.local at DOMAIN.LOCAL (arcfour-hmac) (...)
>> 1 dns-dc2 at DOMAIN.LOCAL (arcfour-hmac) (...)
>> 1 DNS/dc2.domain.local at DOMAIN.LOCAL (aes128-cts-hmac-sha1-96) (...
>> 1 dns-dc2 at DOMAIN.LOCAL (aes128-cts-hmac-sha1-96) (...)
>> 1 DNS/dc2.domain.local at DOMAIN.LOCAL (aes256-cts-hmac-sha1-96) (...)
>> 1 dns-dc2 at DOMAIN.LOCAL (aes256-cts-hmac-sha1-96) (...)
>>
>>
> dns.keytab already exists:
> # ls -l /usr/local/samba/private/dns.keytab
> -rw-r----- 1 root bind 777 Jul 17 21:59
> /usr/local/samba/private/dns.keytab
>
> running the upgrade does not do too much:
> # samba_upgradedns --dns-backend=BIND9_DLZ
> Reading domain information
> DNS accounts already exist
> No zone file /usr/local/samba/private/dns/AD.DOMAIN.CH.zone
> DNS records will be automatically created
> DNS partitions already exist
> dns-dc2 account already exists
> See /usr/local/samba/private/named.conf for an example
> configuration include file for BIND
> and /usr/local/samba/private/named.txt for further documentation
> required for secure DNS updates
> Finished upgrading DNS
>
> and the keytab file is unchanged. Contents looks fine:
> # klist -Kek /usr/local/samba/private/dns.keytab
> Keytab name: FILE:/usr/local/samba/private/dns.keytab
> KVNO Principal
> ----
> --------------------------------------------------------------------------
> 1 DNS/dc2.ad.domain.ch at AD.DOMAIN.CH (des-cbc-crc) (...)
> 1 dns-DC2 at AD.DOMAIN.CH (des-cbc-crc) (...)
> 1 DNS/dc2.ad.domain.ch at AD.DOMAIN.CH (des-cbc-md5) (...)
> 1 dns-DC2 at AD.DOMAIN.CH (des-cbc-md5) (...)
> 1 DNS/dc2.ad.domain.ch at AD.DOMAIN.CH (arcfour-hmac) (...)
> 1 dns-DC2 at AD.DOMAIN.CH (arcfour-hmac) (...)
> 1 DNS/dc2.ad.domain.ch at AD.DOMAIN.CH (aes128-cts-hmac-sha1-96)
> (...)
> 1 dns-DC2 at AD.DOMAIN.CH (aes128-cts-hmac-sha1-96) (...)
> 1 DNS/dc2.ad.domain.ch at AD.DOMAIN.CH (aes256-cts-hmac-sha1-96)
> (...)
> 1 dns-DC2 at AD.DOMAIN.CH (aes256-cts-hmac-sha1-96) (...)
>
> The missing zone file is also not present on the working dc1 system.
>
samba_dnsupdate uses nsupdate to modify dns records the NOAUTH response
is comming from such an nsupdate call.
The samba wiki recommends these settings
kerberos method = system keytab
client ldap sasl wrapping = sign
allow dns updates = nonsecure and secure
nsupdate command = /usr/bin/nsupdate -g
server services = -dns
You can keep your server services line i think.
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