What the purpose of the Option: Do Not Use Recursion

[Guest]

Archived from groups: microsoft.public.win2000.dns (More info?)

In forwarding DNS Cache Servers we can check an option "Do not use
recursion"
What event lead me to use this option? In which situation the option can be
intersting?
When ? Why?

 

[Guest]

Archived from groups: microsoft.public.win2000.dns (More info?)

To fully understand this, you will need to understand the different ways
that a DNS server find a requested record.

This link will give you an idea.
http://www.microsoft.com/windows2000/en/server/help/default.asp?url=/WINDOWS2000/en/server/help/sag_DNS_pro_DisableRecursion.htm

You may want to disable recursion IF you don't want your DNS server to do
too much work. You may want to disable recursion if you don't want other
people to use your DNS server for resolving external records. You may want
to do recursion if you don't want your internal clients to chase down
records themselves.

--
Sincerely,

Dèjì Akómöláfé, MCSE MCSA MCP+I
Microsoft MVP - Directory Services
www.readymaids.com - we know IT
www.akomolafe.com
Do you now realize that Today is the Tomorrow you were worried about
Yesterday? -anon
"Flavio Borup" <borup@running.com.br> wrote in message
news:uVoZqQeiEHA.3172@tk2msftngp13.phx.gbl...
> In forwarding DNS Cache Servers we can check an option "Do not use
> recursion"
> What event lead me to use this option? In which situation the option can
be
> intersting?
> When ? Why?
>
>
>
>

 

[Guest]

Archived from groups: microsoft.public.win2000.dns (More info?)

In news:uVoZqQeiEHA.3172@tk2msftngp13.phx.gbl,
Flavio Borup <borup@running.com.br> wrote their comments
Then Kevin replied below:
> In forwarding DNS Cache Servers we can check an option
> "Do not use recursion"
> What event lead me to use this option? In which situation
> the option can be intersting?
> When ? Why?

This setting effectively disables your server from using root hints to
resolve names and forces it to wait for an answer from its forwarder.

Normally you would not check this option, unless you are using a forwarder
to resolve a name that cannot be found in the public name space, such as
forwarding from a AD child DNS to an AD parent domain or from one AD domain
to another.



--
Best regards,
Kevin D4 Dad Goodknecht Sr. [MVP]
Hope This Helps
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[Guest]

Archived from groups: microsoft.public.win2000.dns (More info?)

Tanks!!

On the Link provided, í've found:

"Disabling the use of recursion on a DNS server is generally done when DNS
clients are being limited to resolving names to a specific DNS server, such
as one located on your intranet. Recursion might also be disabled when the
DNS server is incapable of resolving external DNS names, and clients are
expected to fail over to another DNS server for resolution of these names."
http://www.microsoft.com/windows2000/en/server/help/default.asp?url=/WINDOWS2000/en/server/help/sag_DNS_pro_DisableRecursion.htm



"Kevin D. Goodknecht Sr. [MVP]" <admin@nospam.WFTX.US> wrote in message
news:ejCx3IpiEHA.2180@TK2MSFTNGP10.phx.gbl...
> In news:uVoZqQeiEHA.3172@tk2msftngp13.phx.gbl,
> Flavio Borup <borup@running.com.br> wrote their comments
> Then Kevin replied below:
> > In forwarding DNS Cache Servers we can check an option
> > "Do not use recursion"
> > What event lead me to use this option? In which situation
> > the option can be intersting?
> > When ? Why?
>
> This setting effectively disables your server from using root hints to
> resolve names and forces it to wait for an answer from its forwarder.
>
> Normally you would not check this option, unless you are using a forwarder
> to resolve a name that cannot be found in the public name space, such as
> forwarding from a AD child DNS to an AD parent domain or from one AD
domain
> to another.
>
>
>
> --
> Best regards,
> Kevin D4 Dad Goodknecht Sr. [MVP]
> Hope This Helps
> ================================================
> --
> When responding to posts, please "Reply to Group"
> via your newsreader so that others may learn and
> benefit from your issue, to respond directly to
> me remove the nospam. from my email address.
> ================================================
> http://www.lonestaramerica.com/
> ================================================
> Use Outlook Express?... Get OE_Quotefix:
> It will strip signature out and more
> http://home.in.tum.de/~jain/software/oe-quotefix/
> ================================================
> Keep a back up of your OE settings and folders
> with OEBackup:
> http://www.oehelp.com/OEBackup/Default.aspx
> ================================================
>
>

 

[Guest]

Archived from groups: microsoft.public.win2000.dns (More info?)

In news:ese3PgqiEHA.3348@TK2MSFTNGP12.phx.gbl,
Flavio Borup <borup@running.com.br> wrote their comments
Then Kevin replied below:
> Tanks!!
>
> On the Link provided, í've found:
>
> "Disabling the use of recursion on a DNS server is
> generally done when DNS
> clients are being limited to resolving names to a
> specific DNS server, such
> as one located on your intranet. Recursion might also be
> disabled when the
> DNS server is incapable of resolving external DNS names,
> and clients are
> expected to fail over to another DNS server for
> resolution of these names."
>
http://www.microsoft.com/windows2000/en/server/help/default.asp?url=/WINDOWS2000/en/server/help/sag_DNS_pro_DisableRecursion.htm

I think you have just confused "Disable recursion" on the Advanced tab with
"Do not use recursion" on the forwarders tab. These are two different
settings and do two different things to a DNS server.

You ask about "Do not use recusion" which tells DNS to ignore Root Hints and
get all answers from the forwarder, which must still support recursive
lookups.

"Disable recursion" on the Advanced tab, stops DNS from using forwarders and
Root hints, therefore it effectively stops DNS from resolving any name it
does not have in its zones or cache. (Of course it can't answer from the
cache once TTL runs out on the records in the cache) So you can expect all
external resolution to stop within one day because the default maximum cache
TTL is one day for MS DNS.

A non-delegated root forward lookup zone, in effect stops DNS from resolving
names it does not have in its database because being a root, it is supposed
to know all TLDs.


--
Best regards,
Kevin D4 Dad Goodknecht Sr. [MVP]
Hope This Helps
================================================
--
When responding to posts, please "Reply to Group"
via your newsreader so that others may learn and
benefit from your issue, to respond directly to
me remove the nospam. from my email address.
================================================
http://www.lonestaramerica.com/
================================================
Use Outlook Express?... Get OE_Quotefix:
It will strip signature out and more
http://home.in.tum.de/~jain/software/oe-quotefix/
================================================
Keep a back up of your OE settings and folders
with OEBackup:
http://www.oehelp.com/OEBackup/Default.aspx
================================================

 

[Guest]

Archived from groups: microsoft.public.win2000.dns (More info?)

FB> In forwarding DNS Cache Servers we can check an option
FB> "Do not use recursion" What event lead me to use this option?

<URL:http://homepages.tesco.net./~J.deBoynePollard/FGA/dns-monolithic-server-as-proxy.html#Microsoft>

 

[Guest]

Archived from groups: microsoft.public.win2000.dns (More info?)

DA> You may want to disable recursion IF you don't want your DNS server
DA> to do too much work. You may want to disable recursion if you don't
DA> want other people to use your DNS server for resolving external
DA> records.

He is talking about the atrociously misnamed "do not use recursion"
option, not the "disable recursion" option. (Your confusion here
exemplifies just one of the reasons that this option is misnamed.)

The option should be named "Use forwarding only" or some such.