Troubleshooting networks (as with any computer/system/car/generic problem troubleshooting) is often a case study in logic and common sense. Ned Pyle on the Directory Services team has put together a great post on troubleshooting networks using the built-in Windows Tools.
Hi, Ned here. You may already be asking yourself why I’m writing about network troubleshooting. Isn’t this the Directory Services blog? Don’t we just care about Kerberos and group policies and the like? Shouldn’t the Networking team do all this heavy TCP/IP lifting?
Well, without the network, Active Directory and all its little pieces don’t really amount to much. We are a customer of networking ourselves and that means to be effective DS engineers we have to understand the infrastructure that moves all our data around. Otherwise when this important component fails we can’t really determine if DS is having issues or the underlying structure it relies on is in trouble. To be frank, we work a lot of cases here in 3rd tier support that came in as Directory Services symptoms and left resolved as network issues. At one point, 80% of all our DS cases could be tracked back to DNS configuration problems!
We can’t all be network trace gurus though – it takes a lot of time and experience to get to the point where you can look at a capture in NetMon3.1 (or Wireshark, Ethereal, Packetyzer, etc.) and make meaningful sense of all the details. So what are your options if you suspect a networking problem and you don’t feel that NetMon is in your league? You can call us in Microsoft support, or you can use other tools that are simpler and often just as effective to figure out your issue. That’s what we’ll do today