Tim Moor said:
dear dns gurus,
i'm unsure, when to use conditional forwarding, and when stub zone. as far
i understand, both methods will do the job.
thank you very much for sharing your experience
They solve virtually the same problem so in most cases
it really doesn't matter.
Practically no one can tell you the specific cases which
favor each of these but they are distinguishable in complex
scenarios.
With Conditional Forwarding the Forwarder (set) is
FIXED and must be maintained by the Admin so if the
addresses of the forwarders CHANGE it is up to the
Admin to make the equivalent changes (this is slighly
bad).
BUT on the other hand the Admin gets to "PICK" the
speficic server(s) which will be use and this can be
of benefit if there are many DNS servers and some are
"closer than others" -- DNS doesn't have any concept
of "site" so (in theory) the forwarding server that has
a direct WAN line from San Diego LA probably should
NOT (accidently) forward to the DNS server in New
York City which can happen with Stub Zones....
Stub Zones DNS servers obtain and maintain a list of
ALL the "real" (Primary/Secondary) DNS servers of
the zone by contacting their master, and so if the list of
the IP addresses change or the list of DNS servers changes
they update the list without Admins doing any work.
(This is good) but...
But if the situation mentioned above is likely to be a
problem (DNS server using a VERY remote Forwarder)
then perhaps it is better for the Admin to just take
responsibility and type in the FIXED answer as conditional
forwarding.
Does that make sense?
Also, these two features are NEW to Win2003 so with Win2000
(this is the Win2000 version of the newsgroup) you can't use
either of these and might need to just "hold a secondary" for
the 'other zone'.
Note that a Stub Zone is a "Secondary without most of the records"
-- only the SOA, NS, and A records for the Nameservers are
transferred to a Stub.
This is NOT a big deal for reasonably small zones but it can be
a BIG advantage to hold a Stub instead of a Secondary if the
zone has say 100,000 entries. Most people will only ever need
a FEW of those entries (e.g., DCs, mail servers, maybe a few
other servers, etc.) and those will get cached once resolved.
No need to transfer 100,000 records when only (maybe) 100
will every be needed.
There is another possibility which has been made practical
in Win2003 for the SAME FOREST: AD Integration with
the SCOPE of replication to "Every DNS-DC in the Forest".
This last only makes sense if the "other zone" is in your
forest however -- but that is a common problem for people
with complex forests.
