Linux – dhcpd pool exhaustion – What’s the result

At $former_employer, I modified the OpenBSD dhcpd to understand Option 82 and do address assignment directly on that. As a matter of policy, "if you're coming in on connection X, you have the address assigned to X and if you use a switch to connect multiple computers, that's your own problem", and then just direct assignment based on that.

If you start seriously messing around with Option 82 assignment, it's probably worth doing this. Wasn't too hard, but wasn't trivial either.

This is kind of an old post, but it still comes up in search results, so I'm going to add to it.

First: having two DHCP servers in a subnet is not going to cause problems no matter what, that's a very misleading statement. What will cause issues is two DHCP servers which are offering the same pool of addresses. You can have two servers offering different ranges of IP addresses (like 192.168.1.1-100 on one and .101-200 on a second) within the same subnet without causing any issues at all. In fact, if you want to have redundant DHCP in your network, this is a recommended/best practice way to do it.

Second, here's some instructions from Microsoft which may get someone a little closer if they happen to have a similar issue: http://technet.microsoft.com/en-us/library/ee405264(v=ws.10).aspx