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

(cafbit.com)
354 points timdoug | 5 comments | 12 Jul 11 17:04 UTC | HN request time: 0.866s | source
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jrsmith1279 ◴[12 Jul 11 17:30 UTC] No.2755569[source]▶
I'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.

replies(1): >>2755584 #
1. masklinn ◴[12 Jul 11 17:33 UTC] No.2755584[source]▶
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.
replies(3): >>2755596 #>>2756067 #>>2756152 #
2. MostAwesomeDude ◴[12 Jul 11 17:35 UTC] No.2755596[source]▶
"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.
replies(2): >>2755651 #>>2758109 #
3. daniel_solano ◴[12 Jul 11 17:46 UTC] No.2755651[source]▶
I believe that Android also uses dhcpcd, if I recall correctly from recently browsing the source code. I do not know whether or how Android's dhcpcd may be modified.
replies(1): >>2758116 #
4. kcbanner ◴[12 Jul 11 19:15 UTC] No.2756067[source]▶
I think I'd still prefer the standards compliant client, even if it was a slightly slower. Kicking other users off the network isn't a good thing.
5. simmons ◴[12 Jul 11 19:34 UTC] No.2756152[source]▶
I'm the author of the original blog post. I also ran my tests with a Samsung Series 5 Chromebook. Its DHCP Vendor-Class string is "dhcpcd 5.1.4". The DHCP performance seems fair, around 2 seconds. However, the total network initialization time tends to be a bit longer. It may have some of the same link establishment delays that I'm seeing on my Ubuntu 10.04 EeePC.