Rapid DHCP: Or, how do Macs get on the network so fast?
1–10 of 191 posts
Re: Rapid DHCP: Or, how do Macs get on the network so fast?
#2I'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.
Re: Rapid DHCP: Or, how do Macs get on the network so fast?
#3I've always wondered why my Mac jumps right on the network, while other devices such as my Xbox 360 take a few seconds before the connection is there.
I'd be interested to see how the Google Chrome CR-48 handles DHCP since it seems like it takes a bit of time before getting online and allowing me to log in to it.
Re: Rapid DHCP: Or, how do Macs get on the network so fast?
#4There already exists a minimal DHCP client implementation in the Linux kernel, but it lacks certain features such as configuring the DNS nameservers.
I wonder if it is possible to use the kernel-level DHCP client to instantly request the IP address while asynchronously initiating the more functional user-mode dhclient?
Once dhclient is up, and the kernel DHCP client has obtained an IP address it could just pass that to the DHClient to make another DHCP request with the same IP but the additional DNS nameservers, etc. The DHCP server would just see this as a re-request for the same IP address from the same MAC address and would just re-ACK.
This would save the time it takes to initiate dhclient to then perform the initial IP address check + request.
EDIT: in fact, I don't get (from the OP's link) why dhclient couldn't just be forced to accept the IP address passed to it by the kernel DHCP client, and bind it with the nameservers/any other info locally without needing to make another round-trip to the DHCP server.
Re: Rapid DHCP: Or, how do Macs get on the network so fast?
#5I've always wondered why my Mac jumps right on the network, while other devices such as my Xbox 360 take a few seconds before the connection is there. I'd be interested to see how the Google Chrome CR-48 handles DHCP since it seems like it takes a bit of time before getting online and allowing me to log in to it.
ChromeOS is based on linux, so I'd expect something similar to what Android does: userland dhclient with the same performance profile as the tablet he tested.
Re: Rapid DHCP: Or, how do Macs get on the network so fast?
#6I've always wondered why my Mac jumps right on the network, while other devices such as my Xbox 360 take a few seconds before the connection is there. I'd be interested to see how the Google Chrome CR-48 handles DHCP since it seems like it takes a bit of time before getting online and allowing me to log in to it.
ChromeOS is based on linux, so I'd expect something similar to what Android does: userland dhclient with the same performance profile as the tablet he tested.
"Chrome OS" is Gentoo, not Android. One of my friends has a Cr47 and some hacking exposed dhcpcd inside, with some unspecified patching to bring it down to sub-second DHCP.
Re: Rapid DHCP: Or, how do Macs get on the network so fast?
#7I'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.
Re: Rapid DHCP: Or, how do Macs get on the network so fast?
#8This implementation by the Mac feels wrong. I mean it appears to work, but it seems like a violation of the protocol and can result in problems on the network. Maybe security issues (?). I'm not an expert in any of these things, but I'd love to hear a network protocol/security experts take on this.
Re: Rapid DHCP: Or, how do Macs get on the network so fast?
#9This is a great example of Apple's detail-oriented focus on real-world user experience, and helps explain why people prefer Macs even if they can't always explain why. Lots of little things just work better. You (where "you" == myself and many others, even if not /you/ personally) are left overall with an experience of less frustration.
Re: Rapid DHCP: Or, how do Macs get on the network so fast?
#10Interesting on the perspectives here. My macbook is faster at reconnecting than my linux laptop was, but it's still a few seconds. When I'm opening the lid, I typically still need to wait 2-4 seconds before the network is usable, sometimes it's a bit more. In comparison, it's still faster, but not 'instantaneous' as some people seem to suggest. Neither of my macbooks have been "instant" (but again, certainly faster than other hardware I've owned).