I recently heard about this novel in which Schrodinger's cat and Pavlov's dog team up for an epic adventure, so I went down to my local library to see if they had a copy

The librarian said that my description of the book rang a bell but she wasn't sure if it was there or not ...

A bit of an unofficial post-mortem on #Optus #outage yesterday (please BOOST for visibility!) I have no insider knowledge, all I can do is look at what Optus's networking gear told the rest of the world through #BGP, and make some informed guesses based on that.

The problem yesterday started at about 4am, when Optus told the world 'I no longer have any internet connectivity', and 'Do not send any internet traffic to me, at all'. The technical description is that they withdrew ALL of their routes from the #DFZ (Which is "The Internet", as seen by all the core routers that ACTUALLY control the internet).

However, as a precursor at about 3am there was a hint that things weren't perfect, as there was a flurry of changes from Optus to the outside world saying, roughly, 'Something has changed inside my network, but you can still keep sending me stuff'.

Now, as two final bits of possibly relevant information, the default for maximum-prefix on #Cisco #ASR9000 is 1048576 (this number is 'the number of routes that can be accepted by this router'), and MOST IMPORTANTLY the DFZ ("the internet") has about 980,000 routes in it at the moment. That's only 90k odd routes LESS than the default maximum.

I'd be amazed if Optus has less than 100k internal routes that aren't visible to the internet, but are visible internally.

So here's what I think happened. The at 3am, the first core #router was upgraded, and a new config was put in place. This did not join the network correctly, and things were half broken. What SHOULD have happened is that all the changes should have stopped, and either rolled back, or waited for further investigation (the cause being that more than 1mil routes were visible, causing it to shut down)

However, someone decided 'Well, maybe if we upgrade the SECOND one, that'll fix the first one' at 4am. That broke the SECOND one, and took Optus completely off the internet.

(Continued, see next for why this is far worse than it should have been)

Dunno about you, but an everyday dose of nature is what I need right now! And the #aussiebirdcount starts today!

It's easy to take part - download the app, watch for 20 minutes, count any birds...
Repeat as needed.
Like medicine.
🪶🌿🐦💊🦜🌏🧪
https://aussiebirdcount.org.au/

The thing about arithmetic is that computers are good at it. The point is to figure out what is the good arithmetic to tell the computers to do.

School mathematics has not caught up with this fact. It trains people to do computer-replaceable things, and actively disables the parts of brains that explore.

I don't blame the teachers: I blame the testers.

*Edit:*

I want to express my thanks and appreciation for all the boosts and comments! I had no idea this would get spread so widely, and I'm humbled by the support.

I'll reply to this post with the plan that I have for the next session.

Original post below...

I'm volunteering at my daughter's elementary school by teaching a "coding club" for 5th graders during their lunch and afternoon recess.

It mostly went great, except I left nearly in tears...

One of the kiddos that joined is blind, and I discovered that the coding programs for kids don't appear to be accessible *at all*.

First we tried Swift Playgrounds, but that didn't seem to work with VoiceOver. Then, he said that he's liked ScratchJr. in the past, and he got frustrated with that because he couldn't get his cat to move.

I'm kinda at a loss for how to help him. He left crying because he thinks that he can't get it, but I'm sure he can. Does anyone have any advice?

Thanks!!

#coding #swiftplayground #blind #accessibility #apple #ipad