Networking / Beginners

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Using the netdiag Utility

netdiag is a powerful, network-testing utility that performs a variety of network diagnostic tests that can help you to pinpoint a networking problem. Listing-1 shows the output from a typical execution of the Netdiag command. (I took the liberty of editing it somewhat to make it more compact.) You can scan this listing to see the types of tests that the netdiag command performs.

Unfortunately, the netdiag command is not available for Windows 9x computers (including Windows Me), and it isn't installed by default in Windows XP or Vista. However, you can install it in Windows XP or Vista by inserting your Windows installation disc in your computer's optical drive. If you're asked to reinstall Windows, say no. Instead, choose to browse the install CD. Navigate your way down to the \Support\Tools folder on the install CD and then double-click the Setup.exe icon in the \Support\Tools folder.

The netdiag command has several switches that let you control the output generated by the command:

• /q: Lists only those tests that fail
• /v: Generates verbose output (even more verbose than usual)
• /debug: Generates extremely verbose output - way more than when you use /v
• /l: Stores the output from the command in a file named NetDiag.log
• /fix: Attempts to fix DNS problems that are discovered

Listing-1: Output from the netdiag Command

...............................
   Computer Name: DOUG
   DNS Host Name: Doug
   System info : Windows 2000 Professional (Build 2600)
   Processor : x86 Family 15 Model 2 Stepping 4, GenuineIntel
   List of installed hotfixes :
	Q147222
	Q308677
	Q308678
	Q310601
	Q311889
	Q315000
Netcard queries test . . . . . . . : Passed
Per interface results:
   Adapter : Local Area Connection
	Netcard queries test . . . : Passed
	Host Name. . . . . . . . . : Doug
	IP Address . . . . . . . . : 192.168.168.21
	Subnet Mask. . . . . . . . : 255.255.255.0
	Default Gateway. . . . . . : 192.168.168.254
	Dns Servers. . . . . . . . : 192.168.168.10
				     168.215.210.50
				     192.9.9.3
	AutoConfiguration results. . . . . . : Passed
	Default gateway test . . . : Passed
	NetBT name test. . . . . . : Passed
	WINS service test. . . . . : Skipped
	   There are no WINS servers configured for this interface.
   Global results:
   Domain membership test . . . . . . : Passed
	Dns domain name is not specified.
	Dns forest name is not specified.
   NetBT transports test. . . . . . . : Passed
	List of NetBt transports currently configured:
	   NetBT_Tcpip_{4A526104-BAEB-44F0-A2F6-A804FE31BBAA}
	1 NetBt transport currently configured.
   Autonet address test . . . . . . . : Passed
   IP loopback ping test. . . . . . . : Passed
   Default gateway test . . . . . . . : Passed
   NetBT name test. . . . . . . . . . : Passed
   Winsock test . . . . . . . . . . . : Passed
   DNS test . . . . . . . . . . . . . : Passed
   Redir and Browser test . . . . . . : Passed
	List of NetBt transports currently bound to the Redir
	   NetBT_Tcpip_{4A526104-BAEB-44F0-A2F6-A804FE31BBAA}
	The redir is bound to 1 NetBt transport.
	List of NetBt transports currently bound to the browser
	   NetBT_Tcpip_{4A526104-BAEB-44F0-A2F6-A804FE31BBAA}
	The browser is bound to 1 NetBt transport.
   DC discovery test. . . . . . . . . : Skipped
   DC list test . . . . . . . . . . . : Skipped
   Trust relationship test. . . . . . : Skipped
   Kerberos test. . . . . . . . . . . : Skipped
   LDAP test. . . . . . . . . . . . . : Skipped
   Bindings test. . . . . . . . . . . : Passed
   WAN configuration test . . . . . . : Skipped
   	No active remote access connections.
   Modem diagnostics test . . . . . . : Passed
   IP Security test . . . . . . . . . : Passed
	Service status is: Started
	Service startup is: Automatic
	IPSec service is available, but no policy is assigned or active
	Note: run "ipseccmd /?" for more detailed information
   The command completed successfully