What is the difference between a forwarder and a conditional forwarder?
Mikoyan
forwarder?
Thanks Anastas
Meinolf Weber [MVP-DS]
Hello Mikoyan,
A conditional forwarder is according to the DNS domain name in the query.
For example, a DNS server can be configured to forward all the queries it
receives for names ending with widgets.example.com to the IP address of a
specific DNS server or to the IP addresses of multiple DNS servers.
From:
http://technet.microsoft.com/en-us/library/cc782142(WS.10).aspx
Best regards
Meinolf Weber
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Mikoyan
So if I understand correctly, in the DNS server properties | Forwarders tab,
if 'All other DNS domains' is selected then the DNS server is configured to
*forward* requests to the IP address of a specific DNS server or to the IP
addresses of multiple DNS servers; and if widgets.example.com is selected
then it is configured to *conditionally* forward requests to the IP address
of a specific DNS server or to the IP addresses of multiple DNS servers.
"Meinolf Weber [MVP-DS]" <meiweb@(nospam)gmx.de> wrote in message
news:6cb2911db8fb8...@msnews.microsoft.com...
Ace Fekay [MCT]
"Mikoyan" <Mik...@someisp.com> wrote in message
news:%23Z5%23XLaiK...@TK2MSFTNGP05.phx.gbl...
> Thanks for the reply Meinolf,
>
> So if I understand correctly, in the DNS server properties | Forwarders
> tab, if 'All other DNS domains' is selected then the DNS server is
> configured to *forward* requests to the IP address of a specific DNS
> server or to the IP addresses of multiple DNS servers; and if
> widgets.example.com is selected then it is configured to *conditionally*
> forward requests to the IP address of a specific DNS server or to the IP
> addresses of multiple DNS servers.
>
In summary, that's correct. Conditional forwarding is normally used with
partnership organizations. If you have a trust, for example, you can
conditionally forward to the partner company's DNS server(s) for only their
domain name, but create a general forwarder to the ISP's DNS for everything
else.
--
Ace
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Ace Fekay, MCT, MCITP EA, MCTS Windows 2008 & Exchange 2007, MCSE & MCSA
2003/2000, MCSA Messaging 2003
Microsoft Certified Trainer
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J de Boyne Pollard
M> a conditional forwarder?
There's another way of looking at it, once one realizes that
forwarding applies to the specified domain name and all domain names
below it in the DNS namespace tree. Conditional forwarding forwards
for a sub-tree of the entire DNS namespace. Unconditional forwarding
forwards unconditionally, for the entire namespace tree (i.e. for the
root of the tree and everything below it). In other words, there
isn't really much of a difference, except in what portions of the DNS
namespace tree they apply to, and unconditional forwarding is little
more than a special case, where the root is used as the tree apex, of
conditional forwarding.
There are more significant differences between, say, forwarding and
"stub zones" than between conditional and unconditional forwarding.
Mikoyan
You mention stub zones in your reply.
One would use a stub zone to enable a DNS server hosting a parent zone to
remain aware of the authoritative DNS servers of one of its child zones. In
contrast, a conditional forwarder would be useful in, for example, a company
merger, allowing DNS clients in separate networks to resolve each others
names without resorting to querying DNS servers on the Internet.
Is my understanding correct?
Best Regards, Anastas
"J de Boyne Pollard" <J.deBoyn...@Tesco.NET> wrote in message
news:e0e1e105-69ff-40a6...@f5g2000yqh.googlegroups.com...
Ace Fekay [MVP-DS, MCT]
> Thank you for the reply Jonathan,
>
> You mention stub zones in your reply.
>
> One would use a stub zone to enable a DNS server hosting a parent zone to
> remain aware of the authoritative DNS servers of one of its child zones.
> In contrast, a conditional forwarder would be useful in, for example, a
> company merger, allowing DNS clients in separate networks to resolve each
> others names without resorting to querying DNS servers on the Internet.
>
> Is my understanding correct?
>
>
Just in case I misunderstood you, I apologize, but for a "DNS server hosting
a parent zone to remain aware of the authoritative DNS servers of one of its
child zones," is actually a parent-child delegation. Stubs are references
for nameservers to other zones or namspaces, such as a partner
organization's namespace or in a parent-child delegation. A stub actually
pulls nameserver reference data as a zone transfer for only the SOA, NS, and
glue A resource records returned in response to the query are stored in the
stub zone. When a query comes in for that zone, the stub has the info for
the nameservers of that namespace to resolve it.
In many cases, Conditional Forwarding is used for a partner's namespace, but
a stub can be used. Comparing the two, the advantage of the stub is that it
can be stored in AD as Ad Integrated. This way, all DC/DNS servers in the
replication scope will have a copy of the stub, whereas a Conditional
Forwarder must be created manually on each DNS server. That can be one
drawback, however if the security model of an org states that only one DNS
server will communicate outside, then forwarding from all DNS server will be
pointed to this one DNS server, which then can have a stub or conditional or
general forwarder going outside (whether to the internet or partner).
More info:
Understanding stub zones: Domain Name System(DNS)Jan 21, 2005 ... A stub
zone is a copy of a zone that contains only those resource records necessary
to identify the authoritative Domain Name System (DNS) ...
http://technet.microsoft.com/en-us/library/cc779197(WS.10).aspx
Using stub zones: Domain Name System(DNS)Jan 21, 2005 ... Keep delegated
zone information current. By updating a stub zone for one of its child zones
regularly, the DNS server hosting both the ...
http://technet.microsoft.com/en-us/library/cc775397(WS.10).aspx
Ace
Mikoyan
No apology needed at all, my confusion was in no way due to any of your
explanations, but originated from here:
http://technet.microsoft.com/en-us/library/cc780434(WS.10).aspx
Specifically:
"Stub zones are used when you want a DNS server hosting a parent zone to
remain aware of the authoritative DNS servers for one of its child zones. If
the stub zone for a child zone is hosted on the same DNS server as the
parent zone, the DNS server hosting the stub zone will receive a list of all
new authoritative DNS servers for the child zone when it requests an update
from the stub zone's master server . This method of updating the DNS server
hosting the parent zone maintains a current list of the authoritative DNS
servers for the child zone as they are added and removed."
However, as the links you provide clearly state, Stub zones are for more
than just parent and child zone resolution, but can also be used for
separate DNS namespaces.
Best Regards, Anastas
"Ace Fekay [MVP-DS, MCT]" <ace...@mvps.RemoveThisPart.org> wrote in message
news:%23H4j9Z7...@TK2MSFTNGP04.phx.gbl...
Ace Fekay [MVP-DS, MCT]
> Thanks Ace for the reply,
>
> No apology needed at all, my confusion was in no way due to any of your
> explanations, but originated from here:
>
> http://technet.microsoft.com/en-us/library/cc780434(WS.10).aspx
>
> Specifically:
>
> "Stub zones are used when you want a DNS server hosting a parent zone to
> remain aware of the authoritative DNS servers for one of its child zones.
> If the stub zone for a child zone is hosted on the same DNS server as the
> parent zone, the DNS server hosting the stub zone will receive a list of
> all new authoritative DNS servers for the child zone when it requests an
> update from the stub zone's master server . This method of updating the
> DNS server hosting the parent zone maintains a current list of the
> authoritative DNS servers for the child zone as they are added and
> removed."
>
> However, as the links you provide clearly state, Stub zones are for more
> than just parent and child zone resolution, but can also be used for
> separate DNS namespaces.
>
> Best Regards, Anastas
Hi Anastas,
Yes, that's correct. The article you mentioned gives only a portion of a
stub's possible uses.
Cheers!
Ace