RE: Fowarder failover

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Thanks for response, but... doesn't answer my question. I have forward only
configuration so no root queries.

What I have found is the default forwarder query timeout - 5 seconds - is
still suitable and provides working failover. This is due to client side
interaction, even if client side query - generally 2 seconds - times out
first pass the forwarder list failover will still operate and bring back
successful answer, the second client pass will then have answer.

I have a datacentres infrastructure plus want to populate forwarders list
via GPO. Just want to know if I can get 4 working forwarders; two per
datacentre, or have to use 3 before setting up my policies.

"oz.ozugurlu" wrote:

You have very interesting question, as general having two forwarders should
be enough and I would enable “the root hints option beside forwarders if the
forwarders won't response the queries” in case.
Assuming your servers do have internet connectivity , ISP DNS servers are
down or not answering the recursive queries as well as root hint server, Then
I would say nothing to worry about because the entire internet will be down
(-:, you can safely ignore anything in regards to external connectivity
--oz

--
Oz Ozugurlu
MVP (Exchange)
MCITP (EMA), MCITP (EA),MCITP (SA)
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http://smtp25.blogspot.com (Blog)


"BenP" wrote:

I can't seem to find any information from MS about how many servers in a
forwarder list will be tried before queries are failed.

In O'Reilly DNS on Windows Server 2003 it says 6 servers can be configured.
There is no limit on how many servers can actually be entered in the list.

However when I have tested failing over DNS Server only seems to attempt the
first 3 forwarders in the list (netmon trace).

Is this a configurable parameter (registry) or fixed limitation?

Thnx
.

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