How OpenBSD's pf source-hash maps internal IPs to NAT pool IPs
OpenBSD's pf packet filter has a feature where you can NAT yourinternal IP addresses to a pool of gateway IP addresses, wherethe pool is specified as a CIDR netblock. The pf.conf manpage describes thevarious options one has for how this happens. If you need a randomlydistributed but consistent mapping, source-hash is what you want.
(Random distribution makes all of your gateway IP addresses more or lessevenly used, regardless of how you distribute IPs around your internalIP address space. Consistent means
閱讀的成本 2之1
這個問題,或許能理解為「一本書的價錢應該以甚麼來衡量」,換句話說,是甚麼使得一本書比另一本書昂貴。對以前的我來說,這是很容易回答的,因為書本就等如知識,隨著知識等級越高書本就越貴
The consequence of Oracle's Solaris decisions
The title of this is a little bit misleading; ultimately, the reallyimportant thing about Oracle's Solaris decisions is not what those decisions are, it isabout how they were implemented. I don't like the decisions, but thereal problem is their abrupt, no-warning implementation.
Let me be completely clear here: by making these decisions, Oraclescrewed people. By implementing them with no advance warning, Oraclescrewed people harder.
The consequence of this is that Oracle has lost my trust. I
區區都有骨灰龕 梗有一間左近
New Article: $10 DIY Tripod Case/Adapter for iPhone 4/3G/3Gs

Just posted to the Articles section of the site: DIY $10 iPhone 4 & 3G/3Gs Tripod Adapter/Case
DIY $10 iPhone 4 & 3G/3Gs Tripod Adapter/Case
Please read this article for background/more info: iPhone/iPad external microphones
[ Update ] Here are a few other commercially-available tripod mounts:
- Smartphone Tripod + Mount (review of the unit I bought - only $7!)
- The Glif - (elegant stand/mount for iPhone 4 - $20)
- SnapMount iPhone 4 Tripod adapter (simple yet sturdy - $18)
- OWLE Mount (Crazy expensive, but nice)
- Some other Tripod Mount Ideas

It's the indirect failure modes that will get you
The University of Toronto's Internet link went down recently (well,became really slow and lossy, so we may just be being DDoS'd orsomething). I'm at home, so when I noticed the link problems I shruggedand carried on; it's not as if my home machine depends on stuff fromwork, so I didn't expect anything beyond the annoyance of not being ableto get to work networks.
(Although the network being unreachable was going to be somewhatinconvenient,
The other peculiar effects of grant funding at universities
A long time ago, I wrote about the power that grant funding givespeople at universities . But there's a flip side togrant funding, and it is that people with grant funding often don'treally have money as the business world thinks of it.
From the outside, it looks like people with grant funding are rolling incash; they get hundreds of thousands of dollars, or even million dollargrants. From the inside, though, that money is almost entirely tied downfor very specific things.