Your results do indicate the EDNS issue. It is universal...it kills all 2008 
servers that I have seen using DNS. As for the 2K3 server, who is it's 
forwarder? I will bet it's a 2K8 server.

From: m b [mailto:[email protected]]
Sent: Wednesday, December 15, 2010 12:13 PM
To: NT System Admin Issues
Subject: Re: 2K8R2 DNS anomaly

This becomes more interesting.  ORCA has set up a reply-size test server 
(https://www.dns-oarc.net/oarc/services/replysizetest).  The results look 
backwards to me, but follow the pattern of success/failure.  An indication that 
this does have to do with UDP packet size.

I'm hesitant to start applying the workaround & turning off EDNS capability.  
Contacting firewall team for their input.


C:\Documents and Settings\me>nslookup -type=txt 
rs.dns-oarc.net<http://rs.dns-oarc.net>. (our 2K8 server)
Server:  (our 2K8 server)
Address:  (our 2K8 server)
DNS request timed out.
    timeout was 2 seconds.
*** Request to (our 2K8 server) timed-out

C:\Documents and Settings\me>nslookup -type=txt 
rs.dns-oarc.net<http://rs.dns-oarc.net>. (our 2k3 server)
Server:  (our 2k3 server)
Address:  (our 2k3 server)
DNS request timed out.
    timeout was 2 seconds.
*** Request to (our 2k3 server) timed-out

C:\Documents and Settings\me>nslookup -type=txt 
rs.dns-oarc.net<http://rs.dns-oarc.net>. (our 2k8r2 server)
Server:  (our 2k8r2 server)
Address:  (our 2k8r2 server)
Non-authoritative answer:
rs.dns-oarc.net<http://rs.dns-oarc.net> canonical name = 
rst.x3827.rs.dns-oarc.net<http://rst.x3827.rs.dns-oarc.net>
rst.x3827.rs.dns-oarc.net<http://rst.x3827.rs.dns-oarc.net>       canonical 
name = rst.x3837.x3827.rs.dns-oarc.net<http://rst.x3837.x3827.rs.dns-oarc.net>
rst.x3837.x3827.rs.dns-oarc.net<http://rst.x3837.x3827.rs.dns-oarc.net> 
canonical name = rst.x3843.x3837.x3827.rs.dns-oa
rc.net<http://rc.net>
rst.x3843.x3837.x3827.rs.dns-oarc.net<http://rst.x3843.x3837.x3827.rs.dns-oarc.net>
   text =
        "(our 2k8r2 server) DNS reply size limit is at least 3843"
rst.x3843.x3837.x3827.rs.dns-oarc.net<http://rst.x3843.x3837.x3827.rs.dns-oarc.net>
   text =
        "(our 2k8r2 server) sent EDNS buffer size 4000"
rst.x3843.x3837.x3827.rs.dns-oarc.net<http://rst.x3843.x3837.x3827.rs.dns-oarc.net>
   text =
        "Tested at 2010-12-15 16:55:15 UTC"



On Wed, Dec 15, 2010 at 10:23 AM, VIPCS 
<[email protected]<mailto:[email protected]>> wrote:
Jeffrey just tried an nslookup query (results below) on two WS2K8 servers (one 
is R2) on two different networks and both resolved (both are DCs with DNS 
installed):

Non-authoritative answer:
Name:    www.insead.edu<http://www.insead.edu/>
Address:  213.182.38.52

Is it possible an upstream DNS forwarder is blocking access?


Sincerely,



Jeffrey and Mary Jane Harris

VIPCS

________________________________
From: m b [mailto:[email protected]<mailto:[email protected]>]
Sent: Wednesday, December 15, 2010 11:15 AM

To: NT System Admin Issues
Subject: 2K8R2 DNS anomaly

Within our forest, all domain controllers are DNS servers.  We've been working 
to upgrade from 2K3 to 2K8.  Most of those that are upgraded are 2K8R2, while a 
few are just 2K8.

I have heard some reports from users that they were unable to access certain 
websites that they were able to access from home.  Today's example is 
www.insead.edu<http://www.insead.edu/>.

When I do an nslookup against any of our 2K8R2 DNS servers, the lookup fails to 
resolve.  If I do that same lookup against any 2K3 or 2K8 DNS server, it is 
successful.

I'm not seeing any common event log errors/warnings among the 2K8R2 DNS 
servers.  My only hunch is root hints.  Anyone experienced something similar?

~ Finally, powerful endpoint security that ISN'T a resource hog! ~
~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/>  ~

---
To manage subscriptions click here: 
http://lyris.sunbelt-software.com/read/my_forums/
or send an email to 
[email protected]<mailto:[email protected]>
with the body: unsubscribe ntsysadmin

~ Finally, powerful endpoint security that ISN'T a resource hog! ~
~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/>  ~

---
To manage subscriptions click here: 
http://lyris.sunbelt-software.com/read/my_forums/
or send an email to 
[email protected]<mailto:[email protected]>
with the body: unsubscribe ntsysadmin


~ Finally, powerful endpoint security that ISN'T a resource hog! ~
~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/>  ~

---
To manage subscriptions click here: 
http://lyris.sunbelt-software.com/read/my_forums/
or send an email to 
[email protected]<mailto:[email protected]>
with the body: unsubscribe ntsysadmin

~ Finally, powerful endpoint security that ISN'T a resource hog! ~
~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/>  ~

---
To manage subscriptions click here: 
http://lyris.sunbelt-software.com/read/my_forums/
or send an email to [email protected]
with the body: unsubscribe ntsysadmin

Reply via email to