Troubleshooting guides
Common IT faults explained step by step, with the commands you really need in support. Every guide comes with a lab where you fix the fault yourself.
DNS server not responding: find the cause and fix it
Pinging IP addresses works but websites won't load? Check step by step whether DNS is to blame, find the wrong DNS server and fix it on Windows and Linux.
Read the guide169.254.x.x IP address (APIPA): what it means and how to fix it
Your PC has an address like 169.254.23.7 and no internet? That means the DHCP server didn't answer. Here's how to find out why and fix it.
Read the guideNetwork troubleshooting: the step-by-step method with commands
Systematic, not guesswork: the order in which to check a network problem, from IP configuration via gateway and DNS to the port. With the right commands for Windows and Linux.
Read the guideAD account keeps getting locked out: find the source
You unlock an Active Directory account and ten minutes later it's locked again? Use event 4740 to find the device that keeps using the old password.
Read the guide