On 19/02/2021 18:58, Dale via samba wrote:> (1) I've had very little success in getting a 2nd DC to take over when 
> the 1st DC is down.? While searching for possible causes, I discovered 
> in RSAT that the reverse zone has only the 1st DC listed on the 
> nameserver tab of both DC's, unlike the forward zone, where both are 
> listed.? Additionally RSAT does not allow me to add the 2nd DC to the 
> nameserver tab, instead yielding a "Validation error, please try again
> later" error message.? I assume there is a corresponding samba-tool 
> command to accomplish this, but I have not been able to find it.
It should have both:
root at dc4:~# ldbsearch --cross-ncs --show-binary -H 
/var/lib/samba/private/sam.ldb -b 
'DC=0.168.192.in-addr.arpa,CN=MicrosoftDNS,DC=DomainDnsZones,DC=samdom,DC=example,DC=com'
-s sub '(&(objectClass=dnsNode)(name=@))'
# record 1
dn: 
DC=@,DC=0.168.192.in-addr.arpa,CN=MicrosoftDNS,DC=DomainDnsZones,DC=samdom,DC=example,DC=com
objectClass: top
objectClass: dnsNode
instanceType: 4
whenCreated: 20190726140900.0Z
uSNCreated: 594342
showInAdvancedViewOnly: TRUE
name: @
objectGUID: 89654d6c-f05b-4fd2-9c80-5640d465cbfe
objectCategory: 
CN=Dns-Node,CN=Schema,CN=Configuration,DC=samdom,DC=example,DC=com
dc: @
dnsRecord:???? NDR: struct dnsp_DnssrvRpcRecord
 ??????? wDataLength????????????? : 0x004f (79)
 ??????? wType??????????????????? : DNS_TYPE_SOA (6)
 ??????? version????????????????? : 0x05 (5)
 ??????? rank???????????????????? : DNS_RANK_ZONE (240)
 ??????? flags??????????????????? : 0x0000 (0)
 ??????? dwSerial???????????????? : 0x00036bab (224171)
 ??????? dwTtlSeconds???????????? : 0x00000e10 (3600)
 ??????? dwReserved?????????????? : 0x00000000 (0)
 ??????? dwTimeStamp????????????? : 0x00000000 (0)
 ??????? data???????????????????? : union dnsRecordData(case 6)
 ??????? soa: struct dnsp_soa
 ??????????? serial?????????????????? : 0x00036bab (224171)
 ??????????? refresh????????????????? : 0x00000384 (900)
 ??????????? retry??????????????????? : 0x00000258 (600)
 ??????????? expire?????????????????? : 0x00015180 (86400)
 ??????????? minimum????????????????? : 0x00000e10 (3600)
 ??????????? mname??????????????????? : dc4.samdom.example.com
 ??????????? rname??????????????????? : hostmaster.samdom.example.com
dnsRecord:???? NDR: struct dnsp_DnssrvRpcRecord
 ??????? wDataLength????????????? : 0x001a (26)
 ??????? wType??????????????????? : DNS_TYPE_NS (2)
 ??????? version????????????????? : 0x05 (5)
 ??????? rank???????????????????? : DNS_RANK_ZONE (240)
 ??????? flags??????????????????? : 0x0000 (0)
 ??????? dwSerial???????????????? : 0x0000006e (110)
 ??????? dwTtlSeconds???????????? : 0x00000e10 (3600)
 ??????? dwReserved?????????????? : 0x00000000 (0)
 ??????? dwTimeStamp????????????? : 0x00000000 (0)
 ??????? data???????????????????? : union dnsRecordData(case 2)
 ??????? ns?????????????????????? : dc4.samdom.example.com
dnsRecord:???? NDR: struct dnsp_DnssrvRpcRecord
 ??????? wDataLength????????????? : 0x001b (27)
 ??????? wType??????????????????? : DNS_TYPE_NS (2)
 ??????? version????????????????? : 0x05 (5)
 ??????? rank???????????????????? : DNS_RANK_ZONE (240)
 ??????? flags??????????????????? : 0x0000 (0)
 ??????? dwSerial???????????????? : 0x00036b34 (224052)
 ??????? dwTtlSeconds???????????? : 0x00000384 (900)
 ??????? dwReserved?????????????? : 0x00000000 (0)
 ??????? dwTimeStamp????????????? : 0x00000000 (0)
 ??????? data???????????????????? : union dnsRecordData(case 2)
 ??????? ns?????????????????????? : dc01.samdom.example.com
whenChanged: 20210210114634.0Z
uSNChanged: 1518469
distinguishedName: 
DC=@,DC=0.168.192.in-addr.arpa,CN=MicrosoftDNS,DC=DomainDnsZones,DC=samdom,DC=example,DC=com
>
> (2)? Also, I seem to recall it being stated on this list that in AD, 
> each DC was supposed to be the SOA of its DNS records.? For me, the 
> SOA of both the forward and reverse zones on the 2nd DC is still the 
> first DC, just like a non-AD BIND9 server.? I'm just asking for 
> clarification of what the correct value should be for the SOA on each DC.
>
Yes both DC's should show as being authoritative:
root at dc01:~# host -t soa samdom.example.com
samdom.example.com has SOA record dc01.samdom.example.com. 
hostmaster.samdom.example.com. 245335 900 600 86400 3600
root at dc4:~# host -t soa samdom.example.com
samdom.example.com has SOA record dc4.samdom.example.com. 
hostmaster.samdom.example.com. 245335 900 600 86400 3600
Rowland