Rapid DHCP: Or, how do Macs get on the network so fast?

"This whole notion of being so proprietary in every facet of what we do has really hurt us." Steve Jobs, circa 1997

There is nothing proprietary about this.

Do you have any examples of other vendors using the last assigned address as a default?

Proprietary in the computer sense is generally taken to mean closed source or at least not made available to competitors or others. There's nothing to stop any other systems offering this kind of quick start DHCP service.

Except that it violates the specification right? I guess we're agreeing to disagree on the definition of proprietary. I can buy all of Apple's funky connectors through various suppliers, and maybe even fab them myself, but to me they're still proprietary. Sorry to be pedantic!

Which specification does it violate?

rfc 2131? seems to say the client can ask for an unlimited lease, but the server can specify a finite one. this article seems to be saying that this thing will use the last one leased no matter how long it's been off the network

The DHCP client acts as expected. The behavior observed by the post author occurs before DHCP negotiation executes. I know this seems like a technicality, but it's the truth. The sniffing and assumed use of an IP address occurs outside the DHCP request/response cycle. It's used ahead of time, and discarded if the DHCP 'request' request is denied.

The only people bent about this are people who have any idea what's going on behind the scenes. In the rare cases where this is a problem, the issue is quickly resolved. If this were a "real" problem, we'd have seen a lot more issues by now. The Apple discussion boards would be lit up with complaints. They're not. This is a non-issue. Only pedants are stuck on the fact that there's no RFC for it.