Orly,

Is this what you're seeing?

M. Yu



----- Original Message -----
From: "Ian Watts" <[EMAIL PROTECTED]>
To: "Barry Finkel" <[EMAIL PROTECTED]>
Cc: <[EMAIL PROTECTED]>
Sent: Saturday, November 17, 2001 5:25 AM
Subject: Re: Follow-up: request storms from Windows


>
> Okay, it turns out that this problem arises when the AD servers do a
> lookup for an IP address where the ARPA zone has a CNAME for an NS record.
>
> Example:
>
> ian@squid:~$ dig 88.140.in-addr.arpa ns +short
> artemis.acs.bethel.edu.
> ian@squid:~$ dig artemis.acs.bethel.edu.
>
> ; <<>> DiG 9.2.0rc7 <<>> artemis.acs.bethel.edu.
> ;; global options:  printcmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 61890
> ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 2, ADDITIONAL: 2
>
> ;; QUESTION SECTION:
> ;artemis.acs.bethel.edu.                IN      A
>
> ;; ANSWER SECTION:
> artemis.acs.bethel.edu. 517962  IN      CNAME   amidala.bnet.bethel.edu.
> amidala.bnet.bethel.edu. 517962 IN      A       140.88.128.1
>
> ;; AUTHORITY SECTION:
> bethel.edu.             517962  IN      NS      ns2.onvoy.net.
> bethel.edu.             517962  IN      NS      ns1.bethel.edu.
>
> ;; ADDITIONAL SECTION:
> ns1.bethel.edu.         517962  IN      A       140.88.128.1
> ns2.onvoy.net.          166593  IN      A       206.9.64.104
>
> ;; Query time: 12 msec
> ;; SERVER: 127.0.0.1#53(127.0.0.1)
> ;; WHEN: Fri Nov 16 16:21:21 2001
> ;; MSG SIZE  rcvd: 160
>
>
> I have asked the admins of the Windows servers to "Secure cache against
> pollution", i.e. disable glue fetching.  When they get around to it I'll
> let you know if it makes a difference.
>
> And since you ask, the AD servers are forwarding to my BIND nameservers
> everything that's not in their "domains".
>
> -- Ian Watts
>
>
>
> On Fri, 16 Nov 2001, Barry Finkel wrote:
>
> > Ian Watts <[EMAIL PROTECTED]> wrote:
> >
> > >A while ago I mentioned that I was occasionally seeing large numbers of
> > >identical queries coming from local Win2K Active Directory servers.
Just
> > >yesterday one of them was generating 2,500 identical queries per
second.
> > >
> > >There appears to be a pattern: whenever this happens, it is a request
for
> > >a name that is a CNAME for one of the nameservers for that zone.
Possible
> > >AD bug?  Other?
> > >
> > >I have not duplicated this behaviour myself, but 3 out of 3 rather
> > >particular records is a pattern in my book.
> > >
> > >Examples:
> > >ns1.poweruser.com
> > >artemis.acs.bethel.edu
> > >wks01.clickcom.com
> > >
> > >Although there must be a newsgroup for Active Directory issues, this
may
> > >in fact be something completely different and it impacts us BIND users
> > >negatively.  Anyone have any input on this problem?
> >
> > What is your DNS configuration?  I am assuming that an W2k AD machine
> > was sending multiple DNS lookup requests to your BIND server.  You
> > say that the names being queried are CNAMEs for nameservers.  I wonder
> > if there are DNS zones that have these CNAMEs in NS records.  I know
> > that NS records cannot point to CNAMEs, but if this were to occur and
> > W2k were attempting to contact the real nameserver, would it get into
> > a loop?  I would suggest contacting Microsoft support.  I do not have
> > enough information to attempt to reproduce the problem here.
> > ----------------------------------------------------------------------
> > Barry S. Finkel
> > Electronics and Computing Technologies Division
> > Argonne National Laboratory          Phone:    +1 (630) 252-7277
> > 9700 South Cass Avenue               Facsimile:+1 (630) 252-9689
> > Building 221, Room B236              Internet: [EMAIL PROTECTED]
> > Argonne, IL   60439-4844             IBMMAIL:  I1004994
> >
> >
>
>
>

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