Troubleshooting DNS on a Windows server

Earlier today, I blogged about some of the tools that are available for monitoring Active Directory (AD) enterprise replication and troubleshooting Windows authentication. Given that AD is so heavily reliant on the domain name system (DNS), it seems logical that I also list some of the tools available for monitoring and troubleshooting DNS issues.

The first port of call is the Windows version of the original Unix DNS lookup tool (nslookup.exe). Typing nslookup at a command prompt enters the nslookup shell, from where issuing the help command will list all of the available options.

The DNS server troubleshooting tool (dnscmd.exe) is a support tool for Windows 2000 Server and Windows Server 2003 (available on the Windows installation media) which allows administration of DNS from a command prompt. It extends and replaces the earlier dnsstat.exe tool provided as part of the Windows NT resource kit. The DNS server troubleshooting tool displays and changes the properties of DNS servers, zones, and resource records, manually modifying properties, creating and deleting zones and resource records, and forcing replication events between DNS server physical memory and DNS databases and data files. Some operations of the tool work at the DNS server level while others work at the zone level. Simply type dnscmd for usage information.

DNS has its own set of performance counters available under the performance monitor DNS object.

The domain controller diagnostic tool (dcdiag.exe) checks DNS functionality as part of its diagnostic tests but the command to specifically test DNS registration (which does not need to be run from a domain controller) is dcdiag /test:registerindns /dnsdomain:domainname.

The network connectivity tester (netdiag.exe) helps to isolate networking and connectivity problems by performing a series of tests to determine the state of a network client to identify and isolate network problems. Parsing the output for “DNS test” will give DNS-specific results. Type netdiag /? for usage information.

DNS debug logging may be set in the DNS server properties and creates a log file at %systemroot%\system32\dns\dns.log for further diagnosis of DNS activity.

Finally, the dnslint.exe support tool allows verification of DNS records for a specified domain name to help diagnose potential causes of incorrect delegation and other common DNS problems, producing an HTML report. Usage information can be obtained by issuing the dnslint /? command.

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