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I have a Windows 2008 R2 domain controller which is also a DNS server. When resolving certain TLDs, it returns a SERVFAIL:

$ dig bogus.              

; <<>> DiG 9.8.1 <<>> bogus.
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 31919
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;bogus.             IN  A

I get the same result for a real TLD like com. when querying the DC as shown above. Compare to a BIND server that is working as expected:

$ dig bogus. @128.59.59.70

; <<>> DiG 9.8.1 <<>> bogus. @128.59.59.70
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 30141
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;bogus.             IN  A

;; AUTHORITY SECTION:
.           10800   IN  SOA a.root-servers.net. nstld.verisign-grs.com. 2012012501 1800 900 604800 86400

;; Query time: 18 msec
;; SERVER: 128.59.59.70#53(128.59.59.70)
;; WHEN: Wed Jan 25 14:09:14 2012
;; MSG SIZE  rcvd: 98

Similarly, when I query my Windows DNS server with dig . any, I get a SERVFAIL but the BIND servers return the root zone as expected.

This sounds similar to the issue described in http://support.microsoft.com/kb/968372 except I am using two forwarders (128.59.59.70 from above as well as 128.59.62.10) and falling back to root hints so the preconditions to expose the issue are not the same. Nevertheless, I also applied the MaxCacheTTL registry fix as described and restarted DNS and the whole server as well but the problem persists. The problem occurs on all domain controllers in this domain and has occurred since half a year ago, even though the servers are getting automatic Windows updates.

EDIT

Here is a debug log. The client is 160.39.114.110, which is my workstation.

1/25/2012 2:16:01 PM 0E08 PACKET  000000001EA6BFD0 UDP Rcv 160.39.114.110  2e94   Q [0001   D   NOERROR] A      (5)bogus(0)
UDP question info at 000000001EA6BFD0
  Socket = 508
  Remote addr 160.39.114.110, port 49710
  Time Query=1077016, Queued=0, Expire=0
  Buf length = 0x0fa0 (4000)
  Msg length = 0x0017 (23)
  Message:
    XID       0x2e94
    Flags     0x0100
      QR        0 (QUESTION)
      OPCODE    0 (QUERY)
      AA        0
      TC        0
      RD        1
      RA        0
      Z         0
      CD        0
      AD        0
      RCODE     0 (NOERROR)
    QCOUNT    1
    ACOUNT    0
    NSCOUNT   0
    ARCOUNT   0
    QUESTION SECTION:
    Offset = 0x000c, RR count = 0
    Name      "(5)bogus(0)"
      QTYPE   A (1)
      QCLASS  1
    ANSWER SECTION:
      empty
    AUTHORITY SECTION:
      empty
    ADDITIONAL SECTION:
      empty

1/25/2012 2:16:01 PM 0E08 PACKET  000000001EA6BFD0 UDP Snd 160.39.114.110  2e94 R Q [8281   DR SERVFAIL] A      (5)bogus(0)
UDP response info at 000000001EA6BFD0
  Socket = 508
  Remote addr 160.39.114.110, port 49710
  Time Query=1077016, Queued=0, Expire=0
  Buf length = 0x0fa0 (4000)
  Msg length = 0x0017 (23)
  Message:
    XID       0x2e94
    Flags     0x8182
      QR        1 (RESPONSE)
      OPCODE    0 (QUERY)
      AA        0
      TC        0
      RD        1
      RA        1
      Z         0
      CD        0
      AD        0
      RCODE     2 (SERVFAIL)
    QCOUNT    1
    ACOUNT    0
    NSCOUNT   0
    ARCOUNT   0
    QUESTION SECTION:
    Offset = 0x000c, RR count = 0
    Name      "(5)bogus(0)"
      QTYPE   A (1)
      QCLASS  1
    ANSWER SECTION:
      empty
    AUTHORITY SECTION:
      empty
    ADDITIONAL SECTION:
      empty

Every option in the debug log box was checked except "filter by IP". By contrast, when I query, say, accounts.google.com, I can see the DNS server go out to its forwarder (128.59.59.70, for example). In this case, I didn't see any packets going out from my DNS server even though bogus. was not in the cache (the debug log was already running and this is the first time I queried this server for bogus. or any TLD). It just returned SERVFAIL without consulting any other DNS server, as in the Microsoft KB article linked above.

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So turn on debug logging and find out exactly what's happening at the back end for these queries. Then tell us what the server has recorded, in your question. –  JdeBP Jan 25 '12 at 19:58

1 Answer 1

We have had similar issue on Microsoft DNS servers with no forwarders configured. Looks like this hotfix is related: http://support.microsoft.com/kb/2508835 . I wouldnt say that using forwarders would negate the applicability.

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