Today a conversation
at my job came up about setting the preferred DNS server on the NIC of a DC
with DNS installed.
For as far as I know
it's best to point the DC (with DNS installed) to itself for DNS by
specifying the internal IP address of the DC as the preferred
DNS
server on the
NIC.
Then I was told that
this is not always necessary and this puzzled me a bit.
Not everybody was
convinced of the above and this got me thinking. Some people are claiming
that it doesnt really matter if you set that DC to be the
preferred or the alternate DNS server.
I was then showed an
environment where all DC's in a child domain (all had DNS installed), had the
same DNS server set as preferred DNS server.
Perhaps
an example will make it more clear:
a forest root domain
with 4 child domains.
child domain A, B,
C, and D.
Names of the Domain
Controllers:
root domain: DC-A
& DC-B & DC-C & DC-D
for child domain A:
DC-A1 & DC-A2
for child domain B:
DC-B1 & DC-B2
for child domain C:
DC-C1 & DC-C2
for child domain D:
DC-D1 & DC-D2
DC-A1 has specified DC-A2 as preferred DNS server and has specified DC-A1
(itself) as alternate DNS server.
DC-A2 has specified
DC-A2 (itself) as preferred DNS server and has specified DC-A1 as alternate DNS
server
DC-B1 has specified DC-B2 as
preferred DNS server and has specified DC-B1 (itself) as alternate DNS
server
DC-B2 has specified DC-B2
(itself) as preferred DNS server and has specified DC-B1 as alternate DNS
server
And so on for the other child
domains.
I was told that this was done because this
AD environment was not optimal and that by pointing all the
dc's in a child domain to the same DNS server, other issues were prevented
from occuring.
This didnt sound all that good to me to be honoust
:-)
I am now wondering if there are scenario's
thinkable when it would be better not to point a DC with DNS installed as
the preferred server on it's NIC.
Does the term Island DNS also play a role in
this?
