I remember that there are test patterns built into T1 CSU/DSUs, but not what they are or how to turn them on – if I need to know, I’ll look it up.

I remember that there are three QoS bits in the IPv4 header, but not where they are. Probably pretty early, because of hardware implementations.

I remember that lots of people look down on Perl 5’s object system, but not why. I remember the existence and purpose of lots of Perl modules, but not the interfaces.

I edit JSON and YAML every few weeks, but I don …

Recognize this pattern:

• Set a goal
• Work towards the goal
• Evaluate progress:
• If it didn’t get closer to the goal, try a different approach.
• If it got closer to the goal, try improving it.
• Cycle.

That seems reasonable, right? It accomplishes what you wanted to do, possibly in a naive manner.

Several people have asked me recently what hardware I would buy today for use as a home firewall.

About a year ago, we switched ISPs from RCN to Verizon. I had no particular issues with RCN except that their prices went up each year without providing better service. (It’s true that RCN also fails to handle IPv6 natively, but Verizon shares that failure.) What’s happened in that year?

• Three outages. Two were caused by trucks knocking down the fiber crossing the road; one by an unspecified problem that was fixed by rebooting the Optical Network Terminal (i.e. fiber termination device, which offers ethernet, cable TV and telephone services). The first fiber outage took a week …

In the distant past, the functions of author, editor and page designer were separated. The author wrote things; the editor fixed errors (both objectively and subjectively) and selected choice bits to highlight; the page designer made things look the way they should. The editorial intermediary didn’t consult the author much, and gave limited direction to the page designer.

Pull quotes appeared where the page designer put them.

Because the editor could not predict where the pull quote would be located on the page, it made sense that the quote would not actually be removed from the text body, but …

All email disclaimers are utterly useless – except, possibly, one that a lawyer sends you that, on that particular message, reminds you that you are not in a privileged relationship.

Here’s the proof:

This message (including any attachment(s) hereto) is confidential and may also be privileged. It is intended solely for the addressee. If you are not the intended recipient you are hereby notified that any disclosure, copying, distribution or taking any action in reliance on the contents of this information is strictly prohibited and may be unlawful. If you have received this message in error you are requested …

One problem: we have built an immense network of supercomputers that is essentially a Commons. An abuse of this Commons that would be ridiculously unprofitable if it had to be carried out by humans – say, an expected return of one one-hundredth cent per attempt – is highly attractive to unscrupulous actors who can automate a billion attempts for an expenditure of a few days or weeks worth of setup and expect a hundred thousand dollars of return.

Another problem: there has been little incentive for software developers to guarantee the security (integrity, privacy, trustworthiness) of their products, because they face so …

I work at a small technology company, recently moved from Cambridge to Boston. The new landlords were a little surprised that we wanted to expand the kitchen. This is what we normally supply to our employees and guests:

We have an espresso machine (and will teach you how to use it), a drip machine, a French press, a coffee grinder, a rotating selection of coffees including decaf in the freezer, about twenty kinds of tea/herbal tea/tisanes…

and a refrigerator stocked with skim milk, whole milk, half-and-half, heavy cream (usually), lemon juice, lime juice, soy and/or almond milk …

“Move fast and break stuff” is a decent philosophy if and only if the consequences of breaking stuff are survivable.

• If breaking stuff means that your website looks weird, that’s survivable.

• If breaking stuff means that performance sucks for a while, that’s survivable.

• If breaking stuff causes unavailability during a critical period of end-user demand, a few incidents might be survivable.

• If breaking stuff causes your company to have a terrible reputation for privacy, security, or competency, that might not be survivable.

• If breaking stuff causes your company to divulge financial information, that might not be survivable.

• If …

0.1 First ‘Real’ Job

“Hey, do you want to interview at an ISP? They’re looking for part-time people who can use UNIX.”

Lars (pronounced Larsh) lived across the hall from me in the dorm. Four of us piled into his car, all of us were accepted provisionally as juniormost UNIX people, and I progressed from “sure, I know what Usenet is” to being the Usenet news admin, then a general purpose sysadmin, and eventually to the Director of IT (aka seniormost sysadmin). The beginning was pure luck.

0.2 Traditional Approach

I sent my resume off to a …

Gas ranges have the UNIX nature: they are powerful, can be controlled precisely, and if you only half-know what you are doing, it’s possible to blow up your house. If you do know what you’re doing, nearly any problem can be solved by taking it apart and cleaning things or replacing components.

Electric ranges are like Windows: they might eventually do the thing they’re supposed to do, but it’s hard to control them, there is a propensity to wildly oversteer, and you really don’t get the same power. If it breaks in a way that …

The Amazon Kindle Fire HD10 (2017) is the high-end tablet of their line. The hardware is mediocre and the software is quite bad. I do not recommend you purchase this or any other Fire tablet… unless you have some very specific requirements.

Let’s consider the negatives, first.

Bootloader is locked

Having a locked bootloader means that you can’t replace the OS with a sane one. If you could do that, then all other software problems could be overcome by a slightly technical person. (If you can follow directions well enough, there are good guides for most systems to …

By all means, replace procmail with maildrop.

If you haven’t read a procmailrc in a few months, it’s so much line noise and you need to consult the man pages again.

If you haven’t read a maildrop recipe file, well – here’s a nearly maximum-complexity snippet:

   xfilter "/usr/bin/spamc -U /var/lib/spamassassin/socket"
      if (/^X-Spam-Status: Yes/)
      {   
        to Maildir/spam/
      }

   `reformail -D 16000 duplicate.cache`
   if ( $RETURNCODE == 0 )
       exit

   if (/^X-Facebook.*/:h)
       to Maildir/facebook/

   if (/^Subject: \[Slack\] Notifications.*/:h)
       to Maildir/slack/

You now know how to do 90% of everything you’ll ever want …

The new office is further away from my house but a shorter commute in time.

For the last fourteen or so years, my commute has been one of these variations:

• Walk to a bus stop, catch a bus for an hour, walk to work. Elapsed time 1:25.
• Walk to a bus stop, catch a bus for an hour, take the Red Line, walk to work. Elapsed time 1:30. * Be dropped off at a trolley stop, catch a trolley, change to Red Line, walk to work. Elapsed time 1:05.
• Be dropped off at a Red Line stop, take the Red Line, walk to work. 0:55.

I can still do the last three of those, adding about 5 minutes for a further stop on the Red Line. But I now have a new option:

• Be dropped off at the commuter rail stop, take a train to North Station, walk to work. 0:43.