Is there a standard that allows a device on a network to have its own DHCP server that only gets turned on if there is no other DHCP server on the network? I'm sure it's possible to implement one using dhcp_probe but I was wondering if there's a pre-existing way of doing this.
SnapOverflow
No, there is no standard for this. There are some dhcp servers that provide a intelligent fail over, and others who don't at all.
99% of dhcp deployments just use more than one server, as the client will respond to the first offer it gets. One popular way of prioritize them is by using delayed response on the non-primary one.
One typical way of running multiple servers is to only hand out half of the addresses on the subnet/scope from one server and then the other half from another server. Your pools have to be over sized handle one server completely failing. Aside from that it works well with minimal setup.
As pauska said, there is no standard though.