Netdiag command will allow you to test and isolate network connectivity problems on all types of client computers. Once launched, Netdiag perform a series of tests to determine the operational status of communication between your network and client computers. 

Netdiag is available with the support tools included with Windows Server 2000 and Windows Server 2003. With Windows Server 2008, all these tools have been integrated, allowing the removal of these tools have to deliver media. However the Netdiag was not the subject of integration since the Dcdiag makes network test options equivalent.

The syntax of the command netdiag: 

netdiag[/q] [/v] [/ a] [/debug] [/d:domainname] [/fix] [/dcaccountenum] [/test:TestNamet] [/skip:TestName]

The detailed parameters of the netdiag are:

  • /q: This parameter specifies an output message and simplified display only error messages. 

  • /v: This setting allows you to run Netdiag mode and display detailed information regarding the action taken. 

  • /l: This setting allows you to export the output of the message to a file Netdiag.log. This file will be created in the same directory where the command was executed Netdiag. 

  • /debug: This parameter allows you to execute the command in debug mode. This mode has an output more detailed than the / v. 

  • /d: domainname: This parameter allows you to locate a domain controller in the specified domain. 

  • /fix: This parameter is used to correct minor problems for example relating to the DNS (Domain Name Server) and test domain controller, as follows:
    • DNS: If the computer is a domain controller, Netdiag.exe verifies all the DNS entries in the Netlogon.dns file to determine if they are correct. In addition, Netdiag.exe updates the appropriate entries if it detects a problem.
    • Test domain controller: If the domain GUID cached in a local computer on your primary domain is different than the domain GUID stored in a domain controller, Netdiag attempts to update the domain GUID on the local computer.

  • /dcaccoutenum: This parameter allows you to enumerate the user accounts from the domain controller. 

  • /test: TestName: This setting lets you specify the tests you want to execute. If you want to specify more tests, please separate each name with a space test. TestName must have one of the following values:
    • Autonet: test of the address APIPA (Automatic Private IP Addressing)
    • Bindings: test link
    • Browser: test and redirect the browser
    • Dclist test from the list of domain controllers
    • DefGw: test of the default gateway
    • DNS: DNS test (Domain Name Service)
    • DsGetDc: test of the discovery of the domain controller
    • Ipconfig: test the IP address configuration
    • IpLoopBk: test loopback ping the IP address
    • IPSec: test IPSec (Internet Protocol security)
    • IPX test: IPX Protocol (Internetwork Packet Exchange)
    • Kerberos: Kerberos Test
    • Ldap: Test LDAP (Lightweight Directory Access Protocol)
    • Member: test of belonging to the field
    • Modem: diagnostic modem
    • NbtNm: test name NetBIOS over TCP / IP (NetBT)
    • Ndis: test queries the NIC
    • NetBTTransports: NetBT transports test
    • Netstat: Netstat information test
    • NetWare: NetWare test
    • Road test of the routing table
    • Trust: test Relations Approval
    • WAN: test of the configuration of wide area network (WAN)
    • WINS: test Service (WINS Windows Internet Naming Services)
    • Winsock: Winsock test

  • /skip:TestName : This setting lets you specify the tests that you do not want to run, replacing TestName by one or more elements in the list of parameter / test: TestName. If you want to specify more tests, please separate with a space.