DNS Question: Recursive vs. Iterative

Can someone give me a clear explanation (or point me to a resource on the
Internet) of the difference between recursive and iterative? I've looked it
up in a couple of books and on the web, but I'm still fuzzy on the topic.
Thanks.

kpg
Wed Dec 03 15:02:14 CST 2003

I can give you a progrmmmer's definition of those terms, but I would ask in
what context are you referring to?

recursive - repeating a number of times by re-entering (re-calling) itself
itertive - repeating a number of time by looping (within itself)

(obviously these are not 'technical' definitions...)

recursion is elegent (providing simple code to seemingly complex problems)
but memory intensive

kpg
Wed Dec 03 15:05:17 CST 2003

i am insane

There are three types of queries that a client can make to a DNS server,
recursive, iterative, and inverse.

Recursive queries
In a recursive query, the queried name server is petitioned to respond with
the requested data or with an error stating that data of the requested type
or the domain name specified doesn't exist. The name server cannot just
refer the querier to a different name server.

This type of query is typically done by a DNS client (a resolver) to a DNS
server. Also, if a DNS server is configured to use a forwarder, the request
from this DNS server to its forwarder will be a recursive query.

Iterative queries
In an iterative query, the queried name server gives the best answer it
currently has back to the querier. This type of query is typically done by a
DNS server to other DNS servers after it has received a recursive query from
a resolver.

SWE
Wed Dec 03 15:13:21 CST 2003

so it's not a matter of one or the other? a recursive query can turn into an
iterative query?

what happens if you disable recursion?

"kpg" <kpg@dontcallme.com> wrote in message
news:OV5iDFeuDHA.1876@TK2MSFTNGP09.phx.gbl...
> i am insane
>
> There are three types of queries that a client can make to a DNS server,
> recursive, iterative, and inverse.
>
> Recursive queries
> In a recursive query, the queried name server is petitioned to respond
with
> the requested data or with an error stating that data of the requested
type
> or the domain name specified doesn't exist. The name server cannot just
> refer the querier to a different name server.
>
> This type of query is typically done by a DNS client (a resolver) to a DNS
> server. Also, if a DNS server is configured to use a forwarder, the
request
> from this DNS server to its forwarder will be a recursive query.
>
> Iterative queries
> In an iterative query, the queried name server gives the best answer it
> currently has back to the querier. This type of query is typically done by
a
> DNS server to other DNS servers after it has received a recursive query
from
> a resolver.
>
>
>
>
>
>

oncebitten
Wed Dec 03 15:24:03 CST 2003

SWE wrote:
> Can someone give me a clear explanation (or point me to a resource on
> the Internet) of the difference between recursive and iterative? I've
> looked it up in a couple of books and on the web, but I'm still fuzzy
> on the topic. Thanks.

DON'T ANYONE REPLY!

This is Swen, but he's very cleverly removed the "n" from his name!

This has been a public service announcement from the MCNGP.

--
Fris "We now return you to your usual drivel" bee® MCNGP #13

http://www.mcngp.tk
The MCNGP Team - We're here to help

http://groups.yahoo.com/group/certaholics
Certaholics - We're here if you're beyond help

Consultant
Wed Dec 03 15:30:28 CST 2003

swen, you bastard


"Frisbee® MCNGP" <oncebitten@twiceshy.com> wrote in message
news:%23FDTIPeuDHA.2492@TK2MSFTNGP12.phx.gbl...
> SWE wrote:
> > Can someone give me a clear explanation (or point me to a resource on
> > the Internet) of the difference between recursive and iterative? I've
> > looked it up in a couple of books and on the web, but I'm still fuzzy
> > on the topic. Thanks.
>
> DON'T ANYONE REPLY!
>
> This is Swen, but he's very cleverly removed the "n" from his name!
>
> This has been a public service announcement from the MCNGP.
>
> --
> Fris "We now return you to your usual drivel" bee® MCNGP #13
>
> http://www.mcngp.tk
> The MCNGP Team - We're here to help
>
> http://groups.yahoo.com/group/certaholics
> Certaholics - We're here if you're beyond help
>

SWE
Wed Dec 03 15:32:14 CST 2003

Who the heck is Swen?

"Frisbee® MCNGP" <oncebitten@twiceshy.com> wrote in message
news:%23FDTIPeuDHA.2492@TK2MSFTNGP12.phx.gbl...
> SWE wrote:
> > Can someone give me a clear explanation (or point me to a resource on
> > the Internet) of the difference between recursive and iterative? I've
> > looked it up in a couple of books and on the web, but I'm still fuzzy
> > on the topic. Thanks.
>
> DON'T ANYONE REPLY!
>
> This is Swen, but he's very cleverly removed the "n" from his name!
>
> This has been a public service announcement from the MCNGP.
>
> --
> Fris "We now return you to your usual drivel" bee® MCNGP #13
>
> http://www.mcngp.tk
> The MCNGP Team - We're here to help
>
> http://groups.yahoo.com/group/certaholics
> Certaholics - We're here if you're beyond help
>

SWE
Wed Dec 03 15:32:41 CST 2003

I'm a girl you dingbat. Don't know who Swen is.

"Consultant" <consultant_mcngp_removepants@yahoo.com> wrote in message
news:uOZXbReuDHA.1740@TK2MSFTNGP12.phx.gbl...
> swen, you bastard
>
>
> "Frisbee® MCNGP" <oncebitten@twiceshy.com> wrote in message
> news:%23FDTIPeuDHA.2492@TK2MSFTNGP12.phx.gbl...
> > SWE wrote:
> > > Can someone give me a clear explanation (or point me to a resource on
> > > the Internet) of the difference between recursive and iterative? I've
> > > looked it up in a couple of books and on the web, but I'm still fuzzy
> > > on the topic. Thanks.
> >
> > DON'T ANYONE REPLY!
> >
> > This is Swen, but he's very cleverly removed the "n" from his name!
> >
> > This has been a public service announcement from the MCNGP.
> >
> > --
> > Fris "We now return you to your usual drivel" bee® MCNGP #13
> >
> > http://www.mcngp.tk
> > The MCNGP Team - We're here to help
> >
> > http://groups.yahoo.com/group/certaholics
> > Certaholics - We're here if you're beyond help
> >
>
>

Jtyc
Wed Dec 03 15:39:18 CST 2003

> Who the heck is Swen?

http://securityresponse.symantec.com/avcenter/venc/data/w32.swen.a@mm.html

SWE
Wed Dec 03 15:42:15 CST 2003

so now i'm a mass-mailing worm? gee whiz, way to flatter a woman. i don't
understand what's wrong with asking a dns question in the mcse newsgroup.
how the heck is this considered spam?

"Jtyc" <jtyc_mcngp@f'nspammersdie.yahoo.com> wrote in message
news:%23$YAXWeuDHA.2340@TK2MSFTNGP12.phx.gbl...
> > Who the heck is Swen?
>
> http://securityresponse.symantec.com/avcenter/venc/data/w32.swen.a@mm.html
>
>

kpg
Wed Dec 03 15:39:51 CST 2003

see:

http://www.microsoft.com/windows2000/en/server/help/default.asp?url=/windows2000/en/server/help/sag_DNS_und_HowDnsWorks.htm?id=1945

Ken
Wed Dec 03 15:41:59 CST 2003

> I'm a girl you dingbat.

Oh, well that explains it.


--
<runs from sue>
KB - MCNGP #26

first initial last name AT hotmail DOT com

SWE
Wed Dec 03 15:46:02 CST 2003

really, that explains what?

"Ken Briscoe" <youcant@sendmespam.com> wrote in message
news:uzsyKZeuDHA.2464@TK2MSFTNGP12.phx.gbl...
> > I'm a girl you dingbat.
>
> Oh, well that explains it.
>
>
> --
> <runs from sue>
> KB - MCNGP #26
>
> first initial last name AT hotmail DOT com
>
>

Ken
Wed Dec 03 15:48:35 CST 2003

> so now i'm a mass-mailing worm? gee whiz, way to flatter a woman. i don't
> understand what's wrong with asking a dns question in the mcse newsgroup.
> how the heck is this considered spam?

we're just busting your chops.
1) it's what we do
2) it seems to have been a slow week so far - you're fresh meat

don't take it too personally. or do take it personally, whatever.

--
sorry fellas, hate to see a woman in pain...
KB - MCNGP #26

first initial last name AT hotmail DOT com

Consultant
Wed Dec 03 16:06:38 CST 2003

ah, then please provide your pic. you may email it to me at:

consultant_mcngpyourpants@yahoo.com

remove yourpants to email

"SWE" <me@privacy.net> wrote in message
news:bqlkpf$23h5k8$1@ID-206398.news.uni-berlin.de...
> I'm a girl you dingbat. Don't know who Swen is.
>
> "Consultant" <consultant_mcngp_removepants@yahoo.com> wrote in message
> news:uOZXbReuDHA.1740@TK2MSFTNGP12.phx.gbl...
> > swen, you bastard
> >
> >
> > "Frisbee® MCNGP" <oncebitten@twiceshy.com> wrote in message
> > news:%23FDTIPeuDHA.2492@TK2MSFTNGP12.phx.gbl...
> > > SWE wrote:
> > > > Can someone give me a clear explanation (or point me to a resource
on
> > > > the Internet) of the difference between recursive and iterative?
I've
> > > > looked it up in a couple of books and on the web, but I'm still
fuzzy
> > > > on the topic. Thanks.
> > >
> > > DON'T ANYONE REPLY!
> > >
> > > This is Swen, but he's very cleverly removed the "n" from his name!
> > >
> > > This has been a public service announcement from the MCNGP.
> > >
> > > --
> > > Fris "We now return you to your usual drivel" bee® MCNGP #13
> > >
> > > http://www.mcngp.tk
> > > The MCNGP Team - We're here to help
> > >
> > > http://groups.yahoo.com/group/certaholics
> > > Certaholics - We're here if you're beyond help
> > >
> >
> >
>
>

Consultant
Wed Dec 03 16:07:18 CST 2003

yeah, just take it

"Ken Briscoe" <youcant@sendmespam.com> wrote in message
news:egIw2ceuDHA.1872@TK2MSFTNGP09.phx.gbl...
> > so now i'm a mass-mailing worm? gee whiz, way to flatter a woman. i
don't
> > understand what's wrong with asking a dns question in the mcse
newsgroup.
> > how the heck is this considered spam?
>
> we're just busting your chops.
> 1) it's what we do
> 2) it seems to have been a slow week so far - you're fresh meat
>
> don't take it too personally. or do take it personally, whatever.
>
> --
> sorry fellas, hate to see a woman in pain...
> KB - MCNGP #26
>
> first initial last name AT hotmail DOT com
>
>

Jtyc
Wed Dec 03 16:09:21 CST 2003

> so now i'm a mass-mailing worm? gee whiz,

I didn't call you that. I was just answering your question.


> way to flatter a woman.

I think you're very pretty.

Larry
Wed Dec 03 21:05:35 CST 2003

Down Boy!! <VBEG>

--
Larry Samuels MS-MVP (Windows-Shell/User)
Associate Expert
Unofficial FAQ for Windows Server 2003 at
http://home.earthlink.net/~larrysamuels/WS2003FAQ.htm
Expert Zone - www.microsoft.com/windowsxp/expertzone
"Jtyc" <jtyc_mcngp@f'nspammersdie.yahoo.com> wrote in message
news:%23ZAhJneuDHA.2208@TK2MSFTNGP10.phx.gbl...
> > so now i'm a mass-mailing worm? gee whiz,
>
> I didn't call you that. I was just answering your question.
>
>
> > way to flatter a woman.
>
> I think you're very pretty.
>
>
>

Roger
Sat Dec 06 10:43:21 CST 2003

Check it out - you needed to be more specific.
What is diff between recursive or iterative query,
and what is diff between recursive or iterative server.
Also, there are two Do not use recursion / No recursion
switches in MS DNS server, and they do different things.

--
Roger Abell
Microsoft MVP (Windows Server System: Security)
MCSE (W2k3,W2k,Nt4) MCDBA
"SWE" <me@privacy.net> wrote in message
news:bqlho1$234u0d$1@ID-206398.news.uni-berlin.de...
> Can someone give me a clear explanation (or point me to a resource on the
> Internet) of the difference between recursive and iterative? I've looked
it
> up in a couple of books and on the web, but I'm still fuzzy on the topic.
> Thanks.
>
>

Roger
Sat Dec 06 10:49:04 CST 2003

"kpg" <kpg@dontcallme.com> wrote in message
news:OV5iDFeuDHA.1876@TK2MSFTNGP09.phx.gbl...
> i am insane
>
> There are three types of queries that a client can make to a DNS server,
> recursive, iterative, and inverse.
>
two type of queries


> Recursive queries
> In a recursive query, the queried name server is petitioned to respond
with
> the requested data or with an error stating that data of the requested
type
> or the domain name specified doesn't exist. The name server cannot just
> refer the querier to a different name server.
>

Does not respond with error when name not known
It responds with negetive answer, which is a (non-error) answer
when the name does not exist
Errors are for malformed messages, etc.

> This type of query is typically done by a DNS client (a resolver) to a DNS
> server. Also, if a DNS server is configured to use a forwarder, the
request
> from this DNS server to its forwarder will be a recursive query.
>
> Iterative queries
> In an iterative query, the queried name server gives the best answer it
> currently has back to the querier. This type of query is typically done by
a
> DNS server to other DNS servers after it has received a recursive query
from
> a resolver.
>
Yes, except when it is using its Forwarder

--
Roger Abell
Microsoft MVP (Windows Server System: Security)
MCSE (W2k3,W2k,Nt4) MCDBA