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

I've sat in many a meeting where the Macs "steal" all of the DHCP connections and I'm stuck watching the speaker instead of following TweetDeck.

I've had my wife's macbook bump mine off the network by stealing the IP my machine is using. Definitely an inconvenience when on skype.

Yeah, it does seem like slightly anti-social behaviour (basically, it's asking for forgiveness rather than permission). At least on your home-network, this seems like it could be fixed by assigning your machines permanent addresses or making the router give out much more long lived DHCP leases.

I am not a networking expert, and I haven't looked into this in any greater detail than what was in the article. However, it is possible that the Mac doesn't wait long enough to see if an address is already in use before using it. As such, it may end up essentially being an ARP cache poisoning attack.

How this works out in the end may depend on the DHCP server in use. Perhaps the server may discover the broken ARP resolution and invalidate the lease, allowing the Mac to jump in and steal the address while the other device is still trying to figure out what happened.

On some access points you can disable client to client traffic as a security precaution. If such traffic was disabled, it would probably break the ARP request to see if someone is currently using the IP. (@ 00.0180 seconds in the original article)

I'd like to understand this better. I don't understand what you mean by "steal DHCP connections." Do you mean they use up all of the available DHCP leases? Have you verified this assertion?

I've never observed the behavior you're talking about, and frankly, I suspect that you're just attributing some network failure to a Mac user that just happens to be present.

The only time this should happen is if your router has been rebooted. Otherwise, the Mac is only reusing what should be a valid DHCP lease. If your router is handing out that same IP within the term of the lease expiration, you have bigger problems. If your router is restarted frequently, you should look in to a firmware update to increase the stability.