Windows 7 / Networking

Nslookup

Nslookup (Nslookup.exe) is the primary tool for isolating DNS name resolution problems when connected to the client experiencing the problems. Nslookup is a command-line tool capable of performing DNS lookups and reporting on the results. Other tools, such as PathPing, are capable of resolving host names to IP addresses and displaying the results, but only Nslookup displays the DNS server used to resolve the request. Additionally, Nslookup displays all the results returned by the DNS server and allows you to choose a specific DNS server rather than using the server automatically chosen by Windows.

Nslookup is the correct tool to use when troubleshooting the following types of problems:

  • Clients take several seconds to establish an initial connection.
  • Some clients can establish a connection to a server, but other clients experience problems.
  • The DNS server is configured correctly, but clients are resolving host names incorrectly.

Note The Hosts file, located in the %WinDir%\System32\Drivers\Etc folder, might contain static entries that override DNS lookups for most applications. Nslookup ignores this file, however. If applications resolve a host name differently than Nslookup, verify that the Hosts file does not contain an entry for the host name.

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In this tutorial:

  1. Troubleshooting Network Issues
  2. Tools for Troubleshooting
  3. Table-1 Network Troubleshooting Tools
  4. Arp
  5. How to Identify a Problem with the ARP Cacher
  6. How to Clear the ARP Cache
  7. Event Viewer
  8. IPConfig
  9. Nblookup
  10. Nbtstat
  11. Net
  12. How to View Shared Folders on the Local Computer
  13. How to View Shared Folders on Another Computer
  14. Netstat
  15. Network Monitor
  16. Nslookup
  17. Verifying that the Default DNS Server Resolves Correctly
  18. Verifying that a Specific DNS Server Resolves Correctly
  19. Verifying Specific Types of Addresses
  20. Using TCP for DNS Lookups
  21. PathPing
  22. PathPing Output
  23. Routing Loops
  24. Performance Problems
  25. Possible Connectivity Issues
  26. No Connectivity Issues
  27. Performance Monitor
  28. Data Collector Sets
  29. Windows Resource Monitor
  30. Ping
  31. PortQry
  32. Identifying the TCP Port for a Service
  33. Windows 7 Testing Service Connectivity
  34. Determining Available Remote Management Protocols
  35. Why PortQry Is Great
  36. Route
  37. Task Manager
  38. TCPView
  39. Telnet Client
  40. Testing Service Connectivity
  41. Test TCP
  42. Windows Network Diagnostics
  43. The Process of Troubleshooting Network Problems
  44. How to Troubleshoot Network Connectivity Problems
  45. How to Troubleshoot Application Connectivity Problems
  46. Default Port Assignments for Common Services and Tasks
  47. How to Troubleshoot Name Resolution Problems
  48. How to Verify Connectivity to a DNS Server
  49. How to Use the Hosts File
  50. How to Troubleshoot Performance Problems and Intermittent Connectivity Issues
  51. How to Troubleshoot Joining or Logging on to a Domain
  52. How to Verify Requirements for Joining a Domain
  53. How to Troubleshoot Network Discovery
  54. How to Troubleshoot File and Printer Sharing
  55. How to Troubleshoot File and Printer Sharing from the Client
  56. How to Troubleshoot File and Printer Sharing from the Server
  57. How to Troubleshoot Wireless Networks
  58. Network Diagnostics
  59. How to Troubleshoot Firewall Problems