If for some reason you have a machine that refuses to obtain an IP address, then this section is for you. DHCP issues aren't incredibly common, and thankfully aren't too hard to troubleshoot.

One of the most common issues I've seen with DHCP servers is the date and time of either the server or the client being wrong. In the Linux world, NTP is crucial and should always be working. In the case of DHCP, it only waits so long before the service times out a request for an IP address. If the clock is off by an hour and the incoming request is timestamped an hour ago, that confuses the server and the client will not receive an address. Always ensure that NTP is working on all your clients and servers. DHCP isn't the only service that would suffer with incorrect time on either end. Lot's of strange things can happen in this situation.

A reason for failure is the lack of available IP addresses. This may sound obvious, but you'd be surprised how often this happens. Even...