The Network Files, Case #53: Diagnosing diseases of DNS Presented by Mark Minasi for newsletters, audio sets etc WSV313

2

3

4

7

8

9. (root).com.org.net.uk.gov.ca minasi.commicrosoft.comdoj.gov hq.minasi.com waco.doj.gov test.minasi.com mswatch.doj.gov Top level domainsSecond level domains “sub-domains” or “child domains”

10

11

12 * (it's not really 13 but we'll see that in a bit)

13

14

15

16

17

ISPDNS web2.minasi.com What's the IP address for a.bigfirm.com? Send it to my port 3351 and specify transaction ID (TXID) 279 when you do. "Answer: " sent to port 3351, TXID 279 (The port number and TXID are random numbers with values ranging up to 65,535.) 18

19

20

21

22

23

24

25

26

Then, start up Network Monitor and see a screen that looks something like this (without the Teredo and Isatap NICs): Select the NICs you care about and whether or not you want "promiscuous mode"

Phase 2: window cleanup

29

30

Just the good stuff. 31

32

33

34

Question: "hey, root, ever heard of a.bigfirm.com?" One question, no answers, no authority ("Name ServerCount," no additionals The Question! 35

36 Response: "um, no, but you should next check the.com DNS servers – here are their names and IP addresses" The question count just parrots back the question. There is no answer. The "authority section" offers hints about where to ask the question NEXT with the.com DNS server names. The "additional" section saves you the trouble of having to look up their IPv4 and IPv6 addresses.

37

38 "I don't have the answer, but go ask web2.minasi.com, it will be able to answer your question"

39

40

41

Extensions to DNS a 2008 R2 issue, sort of

43

44

45

46

47

48

49

50 Note the "DnsOverTcp" protocol reference

51

52

53

Tools Some DNS test tools, in brief

55

56

57

58

60

61

62

63

64

65

66

Talk to our Experts at the TLC #TE(sessioncode) DOWNLOAD Windows Server 2012 Release Candidate microsoft.com/windowsserver Hands-On Labs DOWNLOAD Windows Azure Windowsazure.com/ teched

Connect. Share. Discuss. Learning Microsoft Certification & Training Resources TechNet Resources for IT Professionals Resources for Developers

Required Slide Complete an evaluation on CommNet and enter to win!

Scan the Tag to evaluate this session now on myTechEd Mobile