No matter how well you design and secure your network, things will go wrong. Cables get unplugged, DHCP servers run out of leases, wireless clients roam into dead zones and firmware updates introduce new problems. When outages happen, the ability to troubleshoot quickly and methodically is what separates seasoned network professionals from the panicked masses. In this chapter, we’ll build on the monitoring and logging practices you learned earlier to diagnose and resolve a wide range of wired and wireless issues.