Top all-time · #2835
David Simmons
Personal blog · cafbit.com · on HN as simmonssystemsprogramming
David Simmons writes Caffeinated Bitstream, a personal blog at cafbit.com about systems and programming. Since 2011, 27 different Hacker News readers have linked it 34 times, most often “Rapid DHCP: Or, how do Macs get on the network so fast?”. It is still writing: the last post was on 2026-03-28, and you can follow it by feed.
Too few sampled comments (14) to say how often HN recommends it.?
Why HN links it
HN readers link this blog to explain why Apple devices join Wi-Fi networks so quickly, by reusing the last-given DHCP address instead of a full negotiation. A follow-up post is also cited.
Summarised by Claude from a sample of 14 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
The personal blog of David Simmons
Most-linked posts?
- Rapid DHCP: Or, how do Macs get on the network so fast?9 people · 10 mentions · first linked 2011-07-12
- Tokio internals: Understanding Rust's async I/O framework4 people · 4 mentions · first linked 2017-12-18
- Rapid DHCP: Or, how do Macs get on the network so fast? (2011)4 people · 4 mentions · first linked 2017-07-26
- Implementing SCTP to support WebRTC data channels in pure Rust2 people · 2 mentions · first linked 2018-10-08
- Battery cost of periodic mobile network use2 people · 2 mentions · first linked 2014-10-30
- The Lost Art of Threaded Discussions (2009)2 people · 2 mentions · first linked 2011-06-05
What Hacker News says?
You may have been lucky, but I'd suggest looking at http://cafbit.com/entry/rapid_dhcp_or_how_do There's been plenty of debate about whether this rapid DHCP behavior is desirable (e.g. Is the improvement in user experience worth the potential for conflicts and/or other issues on networks not expecting this?), but, either way, I don't see how that behavior can be fairly characterized as polite.
Comment linking /entry/rapid_dhcp_or_how_do
on “iOS 8 randomises the MAC address while scanning for WiFi networks”Submitted Rapid DHCP: Or, how do Macs get on the network so fast? as a story · 354 points
HN discussionWhich MBP do you have? It's fast on Apple products because they 'cheat', and re-use the last-given DHCP address. http://cafbit.com/entry/rapid_dhcp_or_how_do (and the follow up, http://cafbit.com/entry/rapid_dhcp_redux )
Comment linking /entry/rapid_dhcp_redux
on “The sad state of Linux Wi-Fi”Submitted Rapid DHCP: Or, how do Macs get on the network so fast? (2011) as a story · 198 points
HN discussionI would assume related to this. https://www.apple.com/legal/privacy/data/en/location-service... Or potentially to cloud sync this https://cafbit.com/post/rapid_dhcp_or_how_do/
Comment linking /post/rapid_dhcp_or_how_do/
on “Android and iOS data collection”Submitted Tokio internals: Understanding Rust's async I/O framework as a story · 110 points
HN discussionI'm glad to hear I'm not the only one doing this. A colleague and I run a hangout most of every day, and it really makes it feel a lot like being in the same room. (I had to ask the other day -- "Is that your doorbell or my doorbell?) We can quickly ask one-off questions, have impromptu show-and-tell sessions, and of course engage in random brainstorming and "water cooler" talk. It's also easy to tell if the other p…
Comment linking /entry/hanging_out_on_the_job
on “Why We Still Believe in Working Remotely”Submitted Rapid DHCP: Or, how do Macs get on the network so fast? (2011) as a story · 82 points
HN discussionEspecially, mobile devices like laptops, smartphones etc will then have to send probe requests constantly, even if youre away from home... informing any eavesdropper around of essid and probably also bssid. Most OSes do this anyway to speed up the connection process (try to attach to last n networks and see what sticks). Can be abused to learn about past locations of that device by asking one of the wifi location ap…
Comment linking /post/rapid_dhcp_or_how_do/
on “Why the Luddites Matter”Submitted The Lost Art of Threaded Discussions (2009) as a story · 10 points
HN discussionIt's been posted here multiple times: https://cafbit.com/post/rapid_dhcp_or_how_do/
Comment linking /post/rapid_dhcp_or_how_do/
on “Wi-Fi Alliance introduces Wi-Fi 6”Submitted Tokio internals: Understanding Rust's asynchronous I/O framework, bottom up as a story · 4 points
HN discussionThis reminded me of this explanation of how MacBooks (and presumably other devices) manage to reconnect to Wifi so quickly after waking from sleep: http://cafbit.com/entry/rapid_dhcp_or_how_do
Comment linking /entry/rapid_dhcp_or_how_do
on “Why Does It Take So Long to Connect to a WiFi Access Point?”Submitted Tokio internals: Understanding Rust's asynchronous I/O framework as a story · 4 points
HN discussionYes [1], but it's incomplete, needs a lot of TODO resolution and cleanup, (insert other scary disclaimers here), etc. I also have some slides from a presentation [2]. [1] https://github.com/simmons/webrtc-sctp [2] https://cafbit.com/post/rust_webrtc_data_channels/
Comment linking /post/rust_webrtc_data_channels/
on “Show HN: WebRTC implementation for Python using Asyncio”Submitted Using Google Hangouts for collaborative telepresence as a story · 3 points
HN discussionRecommend you have a look at how Apple does DHCP negotiations. http://cafbit.com/entry/rapid_dhcp_or_how_do
Comment linking /entry/rapid_dhcp_or_how_do
on “Experiment in booting Linux fast”Submitted Reinventing software for security; or: The woodpeckers are coming as a story · 2 points
HN discussionApple "cheats" on that regard, getting your wifi back up after sleep. http://cafbit.com/entry/rapid_dhcp_or_how_do http://news.ycombinator.com/item?id=2755461 <-- good discussion
Comment linking /entry/rapid_dhcp_or_how_do
on “Experiment in booting Linux fast”Submitted Recent Android "Package file is invalid" errors as a story · 2 points
HN discussionThat's almost exactly the case. Link here: http://cafbit.com/entry/rapid_dhcp_or_how_do Previous HN discussion here: https://news.ycombinator.com/item?id=2755461
Comment linking /entry/rapid_dhcp_or_how_do
on “Weirdly broken Wi-Fi access points”Submitted Valance64: Control your Windows PC from you Commodore 64 as a story · 2 points
HN discussionYour article doesn't mention it: Have you tried using a statically assigned IP address? (Poor etiquette inside the DHCP range, but maybe if you just snarf the IP you've already leased..) I ask this because OS X's DHCP stack is known to exhibit some strange and unfriendly behaviours: http://cafbit.com/entry/rapid_dhcp_or_how_do
Comment linking /entry/rapid_dhcp_or_how_do
on “Weirdly broken Wi-Fi access points”Submitted Understanding Rust's asynchronous I/O framework from the bottom up (2017) as a story · 1 points
HN discussion> Also, a decent newsreader is still ahead of all modern browser-based software by a mile when it comes to following many discussion threads. For me, nothing today compares with trn. You're far from the only one who feels this way. I'm not quite sure why it is, but I think it's because trn's tree is basically drawn "orthogonally" (if I might use that word), with siblings stacked vertically, and children moving off t…
Comment linking /entry/the_lost_art_of_threaded
on “Usenet, updated in real time as it was thirty years ago”Submitted Implementing SCTP to support WebRTC data channels in pure Rust as a story · 1 points
HN discussionSee this article for some of the optimisations that are possible [1] - not sure which systemd has implemented. [1] http://cafbit.com/entry/rapid_dhcp_or_how_do
Comment linking /entry/rapid_dhcp_or_how_do
on “Network Manager 1.0 Released after 10 years of development”Submitted Battery cost of periodic mobile network use as a story · 1 points
HN discussionWord Writer 4 and an Okidata Okimate 20 printer, here. Some years ago I wrote a quick-and-dirty program to convert the files to HTML [1]... only to be absolutely horrified at how awful my writing was as a teenager. ;) [1] https://cafbit.com/post/migrating_legacy_documents_from_word...
Comment linking /post/migrating_legacy_documents_from_word/
on “Word Writer 6 Commodore 64 Source Code”Submitted Battery cost of periodic mobile network use as a story · 1 points
HN discussion
