DNSLint troubleshooting Utility for DNS
I am always on the lookout for a good new Microsoft utility. DNSLint is my current favourite.
For basic connectivity errors you cannot beat Ping and Ipconfig. But what if they don't solve the problem? The answer is try DNSLint.
Displays port numbers - htm output
Firewall problems plague me, so my killer feature of DNSLint is that it displays port numbers e.g. TCP 53. As a bonus it displays the information as HTML. Perhaps this is the start of a new trend by Microsoft to replace the DOS output of command line utilities is permanent files. (Who remembers to pipe the output of Ipconfig to a text file?)
Where does DNSLint come from?
The first question that I ask about any utility is where do you find it? In the case of DNSLint the answer is: Support Cabinet on Windows Server 2003 CD.
By accident if discovered that to get the most out of DNSLint I needed the a reverse lookup zone. I say by accident as I normally set up a reverse lookup zone as best practice. But I went to a customers site and got egg on my face when DNSLint would not display correctly. I blamed the customer - but only under my breath!
Does DNSLint work with Windows 2000? Yes just provided you have access to the Windows Server 2003 CD.
Getting started with DNSLint - /d /s
As with many of Windows 2003's command line utilities there are whole bank of switches. To get started try DNSLint /d yourdom.com. However there is a trap with /d, if you are NOT connected to the internet. You must add another switch: /s server IP. Technically /s avoids the timeout when DNSLint tries to contact InterNIC whois
Example go to the command line type: DNSLint /d yourdom.net /s 10.1.0.50
The second and subsequent times you run DNSLint, append the /y switch, meaning overwrite the dnslint.htm file. Even better use the /r and specify your own filename. For example, /r serverx.htm, or /t if you prefer a text file.
Troubleshooting Email with DNSLint - /c
Another feature of DNSLint is that it displays MX records which will assist in tracking down email delivery problems. For further email testing, for example SMTP or POP3, try the /c switch. It is possible this only works if the ports are the defaults, 25 SMTP and 110 POP.
To be clear if you just want to test SMTP the command would be:
DNSLint /d guybay.com /c smtp
DNSLint /d guybay.com /c smtp
Checking Active Directory - /ad
To tell the truth I was disappointed with this /ad switch. To be fair it is only designed to troubleshoot forest replication. However I was hoping for a list of _gc or _dc records. I even tried the /v (Verbose) mode - but no dice, just the bare bones of the Glue record for Active Directory Forest replication
Monitor Your Network with the Real-time Traffic Analyzer
The main reason to monitor your network is to check at a glance which of your servers are available. If there is a network problem you want an interface to show the scope of the problem immediately.
Even when all servers and routers are available, sooner or later you will be curious to know who, or what, is hogging the precious network's bandwidth. A GUI showing the top 10 users makes interesting reading.
Another reason to monitor network traffic is to learn more about your server's response times and the consumption of resources. To take the pain out of capturing frames and analysing the raw data, Guy recommends that you download a copy of the SolarWinds.