DNS Question: Recursive vs. Iterative

Discussion in 'MCSE' started by SWE, Dec 3, 2003.

  1. SWE

    SWE Guest

    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.
    SWE, Dec 3, 2003
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  2. SWE

    kpg Guest

    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, Dec 3, 2003
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  3. SWE

    kpg Guest

    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.
    kpg, Dec 3, 2003
  4. SWE

    SWE Guest

    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?
    SWE, Dec 3, 2003

    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

    The MCNGP Team - We're here to help

    Certaholics - We're here if you're beyond help
    =?Windows-1252?Q?Frisbee=AE_MCNGP?=, Dec 3, 2003
  6. SWE

    Consultant Guest

    swen, you bastard

    Consultant, Dec 3, 2003
  7. SWE

    SWE Guest

    Who the heck is Swen?

    SWE, Dec 3, 2003
  8. SWE

    SWE Guest

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

    SWE, Dec 3, 2003
  9. SWE

    Jtyc Guest

    Jtyc, Dec 3, 2003
  10. SWE

    kpg Guest

  11. SWE

    Ken Briscoe Guest

    I'm a girl you dingbat.

    Oh, well that explains it.
    Ken Briscoe, Dec 3, 2003
  12. SWE

    SWE Guest

    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?
    SWE, Dec 3, 2003
  13. SWE

    SWE Guest

    really, that explains what?

    SWE, Dec 3, 2003
  14. SWE

    Ken Briscoe Guest

    so now i'm a mass-mailing worm? gee whiz, way to flatter a woman. i don't
    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.
    Ken Briscoe, Dec 3, 2003
  15. SWE

    Consultant Guest

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

    remove yourpants to email
    Consultant, Dec 3, 2003
  16. SWE

    Consultant Guest

    yeah, just take it

    Consultant, Dec 3, 2003
  17. SWE

    Jtyc Guest

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

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

    I think you're very pretty.
    Jtyc, Dec 3, 2003
  18. Larry Samuels MS-MVP XP \(Shell/User\), Dec 4, 2003
  19. SWE

    Roger Abell Guest

    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, Dec 6, 2003
  20. SWE

    Roger Abell Guest

    two type of queries

    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.
    Yes, except when it is using its Forwarder
    Roger Abell, Dec 6, 2003
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