1. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Network Naming Chapter 10

2. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Objectives Describe the function and capabilities of DNS Configure and troubleshoot WINS Use common TCP/IP utilities to diagnose problems with DNS and WINS

3. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Overview

4. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Introduction to naming Computers use IP addresses to communicate People remember names better than numbers Name resolution created to convert names to IP addresses (and vice versa)

5. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Name resolution has evolved over the years Main protocol is Domain Name System (DNS) Operating systems support old and new Windows, Linux, and Macintosh OS X still support Windows Internet Name Server (WINS)

6. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.1 Turning names into numbers

7. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Three parts to Chapter 10 DNS WINS Diagnosing TCP/IP networks

8. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. DNS

9. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Early Internet use of HOSTS file –One file copied to all hosts on the Internet –Contained a list of IP addresses for every computer, matched to system names –Preceded rules for composing Internet names DNS

10. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. HOSTS file –Preceded DNS –Anyone could name computer anything –Duplicate names not allowed –Sample old HOSTS file: 192.168.2.1fred 201.32.16.4SCHOOL2 123.21.44.16SERVER

11. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. HOSTS file (cont.) –HOSTS file updated on every system every morning at 2 a.m. –Impractical after Internet grew to 5000 –New name system, but HOSTS file still exists –# symbol indicates a line is a comment

12. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. HOSTS file (cont.) –Every OS first looks in HOSTS file –Follow-up to Try This! Every TCP/IP app looks at HOSTS file If you altered the HOSTS file per the Try This!, enter this command: ping timmy

13. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. HOSTS file (cont.) –Some people place shortcut names in a HOSTS file to avoid typing a long name into browser –DNS is more powerful and used much more

14. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. How DNS works –No single computer can handle all Internet name resolution –Delegation used Top-dog DNS system delegates parts of the job Subsidiary DNS systems delegate parts of their work All DNS servers run a special DNS server program

15. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. How DNS works (cont.) –Naming system facilitates delegation –Top-dog DNS a bunch of powerful systems Dispersed around the world Known collectively as the DNS root servers (or DNS root) –The Internet name for DNS root is “.” –Below root are the top-level domain servers

16. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Name spaces –HOSTS file uses a flat name space –DNS uses a hierarchical name space A hierarchy of DNS domains and computer names Hierarchical DNS name space is the DNS Tree Root is the holding area to which all domains connect Individual computers have host names

17. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Name spaces (cont.) –Home-brewed DNS Must not connect to the Internet Set up a DNS server to be the root server

18. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.2 Our People name space

19. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.3 Two DATA.TXT files in different directories on the same system

20. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Name spaces (cont.) –DNS naming syntax Opposite of disk folder/directory syntax A complete DNS name is a fully qualified domain name (FQDN) Host and all domains in order Root is far right

21. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.4 Private DNS network

22. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.5 Two DNS domains

23. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.6 Subdomains added

24. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Key players in DNS –DNS Name Server: running DNS software –DNS Zone: A container for a single DNS domain that gets populated with records –DNS record: a line in the zone data that maps an FQDN to an IP address

25. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Name servers –One server is authoritative DNS server for a domain a.k.a. Start of Authority (SOA) Other name servers (NS) are subordinate All DNS servers know the address of SOA and all NS servers in the domain SOA keeps others updated –Name servers can host multiple DNS Domains

26. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Name servers (cont.) –Other systems send queries to DNS servers –Request resolution of FQDNs to IP addresses

27. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.7 A single SOA can support one or more domains.

28. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.8 DNS flexibility

29. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.9 New information passed out

30. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.10 Root server in action

31. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.11 DNS domain

32. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Name resolution –DNS not required to access Internet –DNS just makes it much easier –IP addresses required for connections –Most people would not use Internet without DNS name resolution

33. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Name resolution (cont.) –Type Web address into a browser –It must resolve the name to IP address –Three ways to resolve a name Broadcasting HOSTS file Querying a DNS server

34. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.12 Any TCP/IP-savvy program accepts either an IP address or an FQDN.

35. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.13 Routers don’t forward broadcasts!

36. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.14 A host contacts its local DNS server.

37. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.15 DNS information in Windows

38. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.16 Entering DNS information in Ubuntu

39. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.17 ipconfig /all showing DNS information in Windows

40. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.18 Checking the DNS cache

41. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.19 Talking to a root server

42. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.20 Talking to the.com server

43. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.21 Talking to microsoft.com DNS server

44. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. DNS servers (in action) –Most OSes have built-in DNS server software Server versions of Windows Most versions of UNIX/Linux –Third-party DNS servers

45. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. DNS Servers (in action) (cont.) –Three special storage areas Cached lookups Forward lookup zones Reverse lookup zones

46. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.22 DNS server main screen

47. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.23 Inspecting the DNS cache

48. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. DNS servers (in action) (cont.) –Cache-only DNS servers Do not store lookup zones Talk to other DNS servers to resolve for clients Are never the authoritative server for a domain

49. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.24 Authoritative vs. cache-only DNS server

50. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Totalhome domain example –Does not comply with Internet rules –None of the computers is visible on Internet –Only usable on private network –Forward lookup is named totalhome –All the DNS servers listed under NS records

51. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Totalhome forward lookup zone –Each system in the domain has an A record –An alias for a system is a canonical name (CNAME) –SMTP servers use MX records (Mail eXchanger) –AAAA records are for IPv6 addresses

52. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.25 Forward lookup zone totalhome

53. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.26 Less common DNS record types

54. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Forward lookup zones –Two types of forward lookup zones: Primary zone and Secondary zone –Resolve FQDN to IP address with Reverse lookup zone

55. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.27 Two DNS servers with updating taking place

56. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.28 Reverse lookup zone

57. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Windows DNS server –Performs most functions exactly like UNIX/Linux DNS servers –Adds a Windows-only Active Directory- integrated zone –Avoids problems of standard DNS servers –All domain controllers are DNS servers –All DNS servers are equal

58. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Enter Windows –1980s Microsoft NetBIOS/NetBEUI –1990s Microsoft created NetBIOS over TCP/IP – added NetBIOS naming to DNS –Old sharing protocol Server Message Block (SMB)

59. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.29 NetBIOS broadcast

60. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Enter Windows—NetBIOS over TCP/IP –New sharing protocol Common Internet File System (CIFS) –SMB/CIFS adopted by UNIX/Linux and Mac OS X –CIFS and DNS work together

61. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.30 Samba on Ubuntu (it’s so common that the OS doesn’t even use the term in the dialog box)

62. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Living with the legacy of CIFS –Networks using CIFS use two name systems –CIFS broadcast to find local server –DNS query to find TCP/IP host –CIFS and DNS work together

63. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Living with the legacy of CIFS (cont.) –CIFS organizes computers into workgroups –Computer joins a workgroup –Flat name space –See workgroups in Network/My Network Places

64. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.31 Joining a workgroup

65. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.32 Two workgroups in Network folder

66. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Living with the legacy of CIFS (cont.) –Computers controlled by Windows domain controller server are grouped in a Windows domain –Windows computers join a domain –Computers (and users) authenticate to the domain –Windows domains now use DNS naming

67. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.33 Logging in to the domain

68. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Living with the legacy of CIFS (cont.) –An Active Directory domain is an organization of computers that shares one or more Windows domains –All Active Directory Windows domain controllers are DNS servers –All domain controllers are equal partners

69. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.34 If one domain controller goes down, another automatically takes over.

70. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Active Directory-integrated zones –DNS info is stored in the AD database, instead of text files –AD is stored across several domain controllers, so there’s no longer only one copy –Domain controllers automatically replicate DNS zone information along with other AD updates

71. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Dynamic DNS (DDNS) –DNS previously required manual updates to zone files –This became very problematic as the Internet and organization’s computers grew in numbers –Dynamic DNS (DDNS) enables a DNS server to talk to a DHCP server and get IP addressing info on its clients

72. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Dynamic DNS (cont.) –Most modern DNS software can use DDNS –Windows clients can also update DNS server files automatically

73. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Dynamic DNS on the Web –High-speed connections now enable home computers to run as web and file servers, and enable remote connections to it –Problem existed with home or office router-assigned DNS names –Dynamic DNS maps home or office router to a domain name

74. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Dynamic DNS on the Web (cont.) –If router’s external IP address changes, it notifies the dynamic DNS service and makes the change –Allows home or office network to be contacted via domain name regardless of IP address changes

75. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Troubleshooting DNS –Client is source of most DNS problems –DNS servers rarely go down –If a DNS server is down, clients use secondary DNS server –Symptom: “server not found” error

76. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.35 DNS error

77. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Troubleshooting DNS (cont.) –Eliminate any local DNS caches Do not use Web browser for troubleshooting On Windows, run ipconfig /flushdns Ping the name of a well-known Web site –Does it return an IP address? –If not, ping an IP address

78. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.36 Using ping to check DNS

79. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Troubleshooting DNS (cont.) –If the previous steps indicate a problem with the DNS server, run nslookup utility Queries functions of DNS servers Depends on proper permission level Use to change how your system uses DNS

80. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Troubleshooting DNS (cont.) –Run nslookup without parameters to get IP address and name of default DNS server Error indicates primary DNS server is down or client has wrong IP for DNS server nslookup has own prompt

81. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Troubleshooting DNS (cont.) –UNIX/Linux tool: domain information groper (DIG) Similar to nslookup Non-interactive Ask it a question; it answers

82. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. WINS

83. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Legacy NetBIOS –Current versions of Windows use DNS and/or CIFS –NetBIOS names supported for backwards compatibility –NetBIOS system broadcasts its name WINS

84. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Prior to CIFS –LMHOSTS file Works for NetBIOS like HOSTS does for DNS Microsoft OSes still support Every Windows systems has an LMHOSTS file

85. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Windows Internet Naming Service (WINS) –WINS server for legacy Windows –No broadcasting: NetBIOS hosts register with WINS –Allows NetBIOS to function in a routed network –WINS proxy agent for legacy Windows

86. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.37 WINS server

87. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.38 Proxy agent

88. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Configuring WINS clients –Enter IP address of WINS server –WINS information can be added to DHCP –WINS clients register NetBIOS names with WINS server

89. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Troubleshooting WINS –Most “WINS” problems are NetBIOS problems Two systems sharing same name Change name of one system –NBTSTAT Check name cache with nbtstat –c Determine if WINS server has given inaccurate info

90. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Diagnosing TCP/IP networks

91. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Improper configuration causes most problems Ping anyone you want to connect to Regardless of what the user cannot connect to, you perform the same steps

92. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Use common sense –If one system behaves differently than others, the problem is with the client –Before starting steps (below) check the network connections and protocols

93. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Steps for troubleshooting TCP/IP –Diagnose the NIC –Diagnose locally –Check IP address and subnet mask –Run netstat with no options –Run netstat –s –Diagnose to the gateway –Diagnose to the Internet

94. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.39 The net view command in action

95. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.40 The netstat command in action

96. Mike Meyers’ CompTIA Network+ ® Guide to Managing and Troubleshooting Networks, Third Edition (Exam N10-005 ) © 2012 The McGraw-Hill Companies, Inc. All rights reserved. Figure 10.41 Using tracert