* Posts by David Crowe

17 posts • joined 19 Jan 2012

This major internet routing blunder took A WEEK to fix. Why so long? It was IPv6 – and no one really noticed

David Crowe

On the Amsterdam Internet Exchange IPv6 traffic is a remarkable 2.6% of all traffic over the past year. It appears to be declining as it was only 2.4% over the past month.

https://stats.ams-ix.net/sflow/ether_type.html

College student with 'visions of writing super-cool scripts' almost wipes out faculty's entire system

David Crowe

I learned (the hard way) never to do anything important with shell scripts. They are like fire. You think you can control them then whoosh, you just burned your house down.

Mourning Apple's war against sockets? The 2018 Mac mini should be your first port of call

David Crowe

OSX Server Software Lives

I was told by someone from Apple a few months ago that Apple would stop supporting their OSX Server software, which would have killed my reason for having a Mac Mini, but hopefully he was giving me erroneous information, and the Server software would live on, because I really don't want to learn how to configure all the Unix configuration files myself.

IPv6: It's only NAT-ural that network nerds are dragging their feet...

David Crowe

Businesses that switch to IPv6 are still dual-stack, so they can't give up IPv4 addresses. Basically IPv6 has NO ADVANTAGES until everyone converts. Which will never happen. So anybody who implements IPv6 is wasting time and money. What we need is IPv7. Admit that IPv6 was a failure and do it right (i.e. as an extension to IPv4 that gradually sucks the life out of its host). IPv6's independence from IPv4 was its fatal flaw.

Sitting pretty in IPv4 land? Look, you're gonna have to talk to IPv6 at some stage

David Crowe

Why would any network demand that you use IPv6 to access it? Unless it wants to cut itself off from a lot of the world?

David Crowe

It'll never work

See my recent article in 2600 magazine: https://cnp-wireless.com/ArticleArchive/2600/IPv6.pdf

OK, this time it's for real: The last available IPv4 address block has gone

David Crowe

Re: I've been trying to get this happening

That's impossible. If you had a service accessible only by IPv6, and people really, really needed it, someone would build an IPv4/IPv6 adapter so that IPv4 could reach it. More likely your service isn't that important and nobody would ever use it, they'd use a similar service that was IPv4 only.

David Crowe

Re: "Nobody uses it..."

I think you mean that we need another octet at the beginning of the IPv4 address.

That's as unlikely as IPv6 ever being widely implemented.

If you consider the port number part of the IPv4 address (which it really is) and less use of port numbers by HTML5 etc., there is no shortage of IPv4 addresses from now until infinity. Sure it's messier than a clean new system, but IPv6 is hardly a clean system, and hardly new.

An 'AI' that can diagnose schizophrenia from a brain scan – here's how it works (or doesn't)

David Crowe

the elephant in the room

The elephant in the room is false positives, that they didn't address. If it was truly 75% accurate then it would diagnose 25% of non-schizophrenic people as schizophrenic. It is probably better than that but even if it's 99% accurate (optimistic!) at not diagnosing healthy people falsely it would still produce 10 false diagnoses out of 1000 scans of healthy people. And let's say the rate of schizophrenia in the general population is 1/1000 (probably less) then false positives would significantly out number true positives. The conundrum of Positive Predictive Value that makes medical screening dangerous.

FOIA documents show the Kafkaesque state of US mass surveillance

David Crowe

Re: To Constitute or not to Constitute...

Arguably, this treatment of British women who were believed to be typhoid carriers was even worse than sleeping with a goat: http://news.bbc.co.uk/today/hi/today/newsid_7523000/7523680.stm

Bloke charged under UK terror law for refusing to cough up passwords

David Crowe

Re: Ugh

Jihadi John, the man who was harassed by authorities until he broke and turned into what the authorities accused him of being. Yes, TWAT is a twat.

Global IPv4 address drought: Seriously, we're done now. We're done

David Crowe

Is 2^48 enough?

If there were truly only 4 billion IPv4 addresses, we'd be f***ked already. But in reality the IPv4 address is essentially combined with the port number (16 bits) through NAT. That gives a theoretical limit of 2^48 addresses, which is: 281,474,976,710,656. Not as many as IPv6, but more than enough. Sure, not all of them could be used, because a server with a static IP address might hog the equivalent of 65k addresses. But there are a lot more client devices out there than servers - mobile devices, IoT modules etc. Basically anything that doesn't need a static IP address to be reached will only use a fraction of a single IPv4 address. And the harder it becomes to get an IPv4 address, the more value there is in reorganizing your network and selling off the majority of the addresses you don't need, and the more creative people will become with efficiency of use of IP addresses and port numbers.

Trump's FBI boss, Attorney General picks reckon your encryption's getting backdoored

David Crowe

Trump is going to make encryption experts' teeth grate again.

IPv4 is OVER. Really. So quit relying on it in new protocols, sheesh

David Crowe

True, but dual stack doesn't solve the problem of running out of IPv4 addresses. And we're not running out of addresses. NAT essentially extends the 32 bit IP address by another 16 bits, which gives you 2^48 addresses. Now admittedly, a lot of the 281 trillion can't be used, but even if 10% can, that's 28 trillion addresses. Even if only 1% can be used, that's still almost 3 trillion addresses. So dual stack solves no problem. We're not really running out of IPv4. What's the point?

David Crowe

I hate to say it, but it's IPv6 that's over. When does IPv6 have any value? When you can communicate with the rest of the internet without an IPv4 address. Dual-stack HAS NO VALUE. It doesn't save IPv4 addresses. This whole exercise is feel good for lovers of IPV6 who won't accept that they've lost. What's needed? A complete redesign with forward and backward compatibility between IPv4 and IPv7. IPv6 was a series of disastrous decisions and it is blocking the progress that would come by starting over.

Google: There are three certainties in life – death, taxes and IPv6

David Crowe

IPv6 is of no value until real people, ordinary people, can configure a device, without an IPv4 address. Having IPv4 + IPv6 does not solve the problem because every device still needs at least one IPv4 addresses. I don't think this day will ever come. We need IPv7, not IPv6. Start from scratch and make it backwards compatible with IPv4. For starters there must be a reserved block for IPv4 addresses (all zeroes plus IPv4 address makes sense) and a mechanism for going IPv4-IPv6-IPv4 and vice versa without losing data or dropping packets. And I mean a single, standardized mechanism. If an IPv7 device could send and receive packets from IPv4 devices then every IPv7 device would save an IPv4 address, and IPv4 would start to dwindle quickly. And it wouldn't matter if it never went away because the smaller it gets the less likely we'll ever run out of IPv4 addresses.

Modeling-clay iPads foisted on unwary Canucks

David Crowe
Linux

iPot

You could easily make an iPot out of the clay, a perfect present for iDad on Father's Day.

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