jyrgenn

Lucy-Anne Holmes: 50 Ways to Find a Lover

2012-01-22T21:53:50Z

When I was in London Easter 2009, I saw an ad for this book in the Underground and took a picture to remember it, because I liked the title. A few weeks ago I noticed the picture again and, as it was just the time for some mindless entertainment, bought the book on the Orinoco Market (or the like) for € 0.01 (yes, really!) plus € 3 for shipping. That should be worth it, I thought. And it was! This is a nice, light comedy, reminding me a bit of Bridget Jones, but maybe even funnier. The (SPOILER!) happy ending with the twist is not a real surprise any more when it finally happens, but (oh the irony!) that was to be expected.

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Michael Crichton: Timeline

2012-01-22T21:43:06Z

This is not the first of Crichton's books I have picked up for a second time. I really liked it on first reading for its fast-paced story-telling and, other than, for instance, the Da Vinci Code, for the story itself. That is what Crichton does (or rather did) so well: write gripping and highly entertaining stories that are not stupid. They may not be the most distinguished and sophisticated art, but page-turners that I don't feel bad about afterwards.

Anyone who, like myself, is not into quantum physics will not really notice the boundary between fact and fiction when that drivel about quantum effects and time travel comes up. This makes the willing suspension of disbelief easy, and it doesn't get into the way of the story. Well, at least for me it works, as the story is good in distracting the reader from the technical things. Have you ever faced a really dangerous and angry knight in a joust who will probably try to kill you as soon as he sees a chance? I thought you haven't.

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Book yield of the fall 2001 vacation, part 2 (paper books)

2012-01-08T19:05:29Z

Apart from the ebooks I read two paper books during this vacation.

Oliver Lepsius, Reinhart Meyer-Kalkus (eds.): Inszenierung als Beruf. Der Fall Guttenberg.: This was the premier political scandal in Germany 2011: After a crowd of anonymous Internet users had proven that his doctorate dissertation had been mostly copied from other sources, the german minister of defense, Karl-Theodor zu Guttenberg, had to step down due to public pressure. "His" university of Bayreuth held a symposium about the case, and the participants' contributions are included in this book. Extremely interesting essays from a number of top intellectuals.
Jacques Berndorf: Eifel-Connection: Berndorf writes whodunit novels placed in the Eifel region of far western Germany, and this is one of them. Like Paretsky's, his protagonist, an aging journalist living on the country, is beaten up in every one of the books, uncovers a major conspiration, and succeeds only with the generous help of his friends. But like hers, his books have a certain, though different, charm about them, which I happen to like.

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Book yield of the fall 2001 vacation, part 1 (ebooks)

2012-01-08T13:38:55Z

Lamenting, as always, the lack of baggage space, the beloved wife and I finally resolved to try ebooks. As a budget-priced option Amazon's new Kindle (the new one without keyboard or touch screen) was chosen, after I had established that it is indeed reasonably possible to read ebooks on it that come from independent sources. It doesn't work with epub, but (for instance) Calibre can convert epub to mobi format. It can also display PDF and plain text documents.

Alas, the selection of ebooks available from Amazon has its shortcomings. Newish books are very similar in price to the print editions, but lack their flexibility -- you cannot easily lend them to others, give them away, resell them, etc. While some of this is possible, as I understand, it is not easy. So this is not an option for the mystery novels the beloved wife consumes at an alarming rate.

But then there are a lot of classics with expired copyright available for free (as in beer, dunno if they are DRMed or not) directly from Amazon, meaning they can be copied to the device with a single click. Lots of others are available from Project Gutenberg in Kindle format, even in German. (BTW, that "Gutenberg-DE" thing is a commercial enterprise that makes it as difficult as possible to download and carry away whole books -- they want you to read the stuff on their site, which generates income by advertising and by selling stuff on CD-ROM.)

Apart from the free stuff there is also a lot of quite cheap content available from Amazon, only not necessarily what you have been looking for. It is worth a look, though.

The Kindle, with 1.4 GB free for books, can hold a lot, given that most books are just a few 100 KB. This is of course excellent for a vacation, and exactly what we had been looking for.

It took me a while to get used to reading stuff on the Kindle and not be distracted by the technical device itself, but after that it is quite pleasant. The hardware is a good compromise between being small and being good to hold in one or two hands. The page turn buttons are very well placed on the sides. The screen is excellent to read when brightly lit and bearable when not so well. I found it useful to adjust the font size accordingly; I use one size smaller than the default with my reading glasses in good light and one size bigger in not-so-good light or with my normal glasses on.

Now, the books:

Neal Stephenson: In the Beginning was the Command Line: This is the first ebook I actually started reading -- I had already begun reading it on the Android phone that I carried for (the previous) work, so it naturally landed on the Kindle as well. I read a bit further into it during this vacation. But the more I read of it, the more I failed to miss his point and wondered "so what is he getting at?" Apart from that, I was more and more annoyed by him not really having understood many of the technical things he talks about.
Sara Paretsky: Hardball: Years ago I have read lots of her V.I. Warshawski novels, and this is another one. Actually the beloved wife wanted to read this one, so it was in German. The translation has a few bugs, but is bearable. It isn't extraordinary, compared to the other ones, even fulfilled more V.I. clichés than I'd have cared for (she gets beaten up multiple times, deeply annoys her late father's police colleagues and other authorities only to be reconciled with the good ones in the end, digs up a major conspiracy, gets close to getting killed, and succeeds only with the help of her close friends), but I still liked it.
Steven Pinker: How the Mind Works: The print edition, even hardcover, has been sitting on my shelf for years, as it is too big and too heavy to read on the move. Now, as an ebook, even relatively cheap for just a bit over € 10, it was easy to carry with me. I began it during this vacation, but didn't get through it. I have read nearly half of it now, and it is still too big. More to the point, I find it too fluffy. So many anecdotes, so much trying to keep it an easy read, all this makes it a bit tiring for me, as the actual information rate is too low and I have to dig through so much fluff. Of course there is is a lot of interesting information in it, and I will read it to the end. But it seems that Pinker's efforts to make the information more accessible have made it less accessible for me.
Hans Christian Nickelsen: Meine lieben Enkel! ("My dear Grandchildren!"): In his last years, my grandfather wrote up some memories, addressed to his grandchildren. This is probably not interesting at all for anyone not related to him or at least very interested in what it meant to be a teacher in the 1930s to 1960s, especially at a german school in the (formerly german) parts of southern Denmark. It is for me, though, and while my father finds it painful to read for all his father's difficult conceptions of his family, my own personal distance is big enough to find it bearable in this respect. I formatted this as a PDF document exactly for the Kindle's page size, so I could choose a type that suits me better than the builtin ones. Unfortunately the dots of the german umlauts (äöü) don't correctly line up with the letters, though.

The final words: Reading ebooks on the Kindle (or any other ebook reader) can be fine, but it has its limitations. Apart from the mentioned consequences of DRM I cannot, for instance, thumb through the book to see how far that particularly boring passage goes, I have to page through it one by one. Most new ebooks are too expensive given the limitations. I find the possibility of putting stuff on the device by USB cable necessary, but also appreciate the ability to load them via email.

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IPv4 Exhaustion Myth

2011-10-22T15:49:14Z

[I enjoyed reading this piece by Daniel Pittman, quoted with permission]

IPv4 exhaustion is just the current part of the natural cycle of rising and falling levels of IPv4 address usage. Besides, many scientists see a significant correlation between sunspot activity and IPv4 consumption.

"The attempts of IPv6 supporters to bolster the myth of human-induced IPv4 exhaustion is downright immoral." Philip Stott, Professor of Bio-geog-ip-ography, University of London

Besides, IPv4 exhaustion is just a theory. It isn't even, like, a real fact or anything. Plenty of scientists believe that there are vast untapped reserves of IPv4 address space lying idle, just waiting for improved routing techniques to release them on the world.

"An IETF IPv4 exhaustion conference in Poland is about to get a surprise from 650 leading scientists who scoff at doomsday reports of man-made IPv4 exhaustion -- labeling them variously a lie, a hoax and part of a new religion."

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Google+ as an Identity Service

2011-08-29T16:58:23Z

If Google wanted Google+ as an identity service, that was well hidden in the beginning. Instead they used the social network surface as a bait, to lure people in, and we came in numbers.

Took me a while to let it sink in. I feel abused, and I hate it that I fell for it.

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Domain Transfer

2011-08-25T08:19:43Z

Years ago (yes, I looked it up) I asked my domain registrar Schlund Technologies to make it possible to register glue records with IPv6 addresses for the name servers. They can do it by hand, but experience has shown that this is an error-prone process. In between they have built a whole new web interface with gratuitous JavaScript overload, and you still cannot do it.

[Update: Apparently I have been wrong here and this is actually possible in between. Sorry, I didn't want to give anyone a bad name.]

A while ago I created an account with Domain Discount 24, where this is actually possible. The impending end of my current ISP contract made some changes necessary, so I transferred my main infrastructure domain w21.org there. Before that, I changed the domain's name servers to some outside of that domain (ns{1,2}.w21-4.de -- only the names, though, same servers actually), to avoid glue record confusion. This may have been unnecessary.

This was the first registrar-to-registrar domain transfer I made, and I must say I am impressed. The whole process, once I found out that I had to put not only the domain name, but separated by a space also the authinfo into that box, took well under an hour, with no perceptible service outage. I had canceled the domain with pre-ack at Schlund earlier, though.

Changing the name servers back to ns{1,2}.w21.org (to make lookups a bit faster) was nearly instantly done and visible at the name servers, and the correction of a typo I made (apparently the .org registry checks less strict than .de, or is it Schlund?), showed up inside of one or two minutes at the .org name servers. Obviously they do not do it with a zone file reload every hour.

Maybe I will transfer my domains all to Domain Discount 24. Or should I not put all my eggs in one basket, perhaps?

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Configuring the SRX100

2011-08-22T08:43:22Z

The need to switch ISPs finally pushed me to configure the Juniper SRX100 router.

As my current ISP, KGT New Media, is giving up their consumer Internet access over T-DSL product and has canceled the contract to end of August, I am a bit under pressure to get everything running with a different ISP. So, back to Titan Networks, although their offer is not quite what I was looking for. For € 24.50 per month, about the same price as with KGT, I get not a traffic flat rate, but a volume of 25GB, with extra traffic for € 5.50/GB. This should usually be enough, but in the past I have had a huge traffic peak once, which suddenly cost me additional 90 Euros. But there are not very many ISPs offering IPv6 for end customer prices to choose from.

Of course, before I switch completely, particularly all the DNS entries for- and backwards, I want to make sure everything works. This gave me another opportunity and additional motivation to finally tackle the SRX100, and I did.

While the Cisco 1712 still runs with KGT, the SRX100 is now running the Titan connection, although in a kind of "client-only" mode, without allowing incoming connections. Making incoming traffic possible requires much more firewall-fu than the little I have already understood. This is really not easy.

Doing the basic configuration -- forwarding IPv4 and IPv6 between the core and the WLAN network and the PPPoE connection to the ISP -- was moderately simple. Junos configuration is indeed a bit less of a pain in the back than IOS. I especially like the method of modifying a configuration until it is done and only then committing it to be activated. Otherwise it would have been more difficult or required a reboot to do reconfigurations that would have cut me off from the router in mid-change.

I also think the explicitly hierarchical configuration makes sense as a way of structuring everything; when I dive into some hierarchy level, I can concentrate on just that and show just that bit, for instance. Ah, yes, you can show the configuration while editing, isn't that just amazing? (I probably have only missed that with IOS, but to me it's still a difference.) And then there are the little things, like being able to go back in the pager (while viewing configuration or the like). I like it.

One thing had me busy for a while, though: There is no possibility to use IPv6 with vlan interfaces. This restriction still puzzles me, but apparently it is intentional, or at least specified. That I was not able to set an IPv6 address on a vlan interface from the CLI but could do that from the web interface added to my confusion. But even if an address has been set on a vlan interface, it cannot actually be used. Took me quite a while to find the final answer.

In the end I gave up and configured the interfaces not as switching group members, but as IP interfaces, and then everything worked. Well, except for the switching, of course -- I need a separate switch now where a port-based vlan on the SRX100 should have been sufficient. That is annoying.

Apart from that and the still unresolved incoming traffic issue, everything works fine now.

Perhaps I will finally just switch the Cisco over to Titan, and then the SRX100 to the currently unused T-Online connection -- I used it briefly for testing the SRX100 and found it that instead of the 30 ms roundtrip to my external server, it gave me 8! The T-Online access is with IPv4 only (currently; IPv6 probably next year) and with changing addresses. But that is fine for the clients, while the server can still use the fixed-address IPv6 and IPv4 access over the Cisco and Titan.

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Peter Seibel: Coders at Work

2011-08-13T10:18:12Z

A review by Russ Allbery and subsequent discussion pointed me to this book. I agree totally with him, so no need to repeat everything he said. This is indeed an immensely interesting book. The best thing about it is that it made me reflect about my own programming as well. For instance, with all these illustrious role models doing the same, I now feel less guilty about some things that I do myself, such as not diving deeper into the intricacies of debugging using gdb and things, but just going the easy way using debug printouts to learn about the state of my program. Or just rewriting passages of my code that I don't really understand instead of finding the bug and fixing it.

I also agree with Russ's rating of the book, 10 of 10 points. And apparently it is quite a success, too; when I recently mentioned the book to two of my colleagues, both had already read it.

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Catriona McCloud: Growing Up Again

2011-07-17T13:49:33Z

The house we had near Gdansk had a small selection of books, most in English. Realizing after a few days that my own choice of books that I had brought with me was not really fit for the occasion, I took one of those. I didn't get through it during that week, but I could buy it used later over Amazon for € 0.01 plus € 3.00 for shipping. (Why do they do that? There cannot be much profit in that, can it?)

In early 2002 Janie, in her later 30s, decides to separate from her husband, for whom she has lost the respect, although not the love. When she wakes up the next day, she realizes she is back at her parents' home and 16 years old, but still with the knowledge and consciousness of her previous existence. After the initial confusion she settles into her new old role of 1981 and prepares for making everything better. That includes making some money from the knowledge she has (by buying shares of IBM and Tesco), but also saving Lady Di and Prince Charles from their ill-fated marriage, making more mature decisions regarding the people in her life, and above all preparing for the day when she meets her to-be husband, with the aim to make their relationship better as well as him a better man.

As the reader has suspected long before, this does not work out. Instead, her life takes a quite different course. All the while she wonders what the exact purpose was of sending her into the past -- there must be one, as there are some mysterious people involved in her fate, but instead of putting her in the know, they just tell her to wait for later instructions all the time.

I found the book a bit disappointing at the end. A big surprise was not totally unexpected as such at that point, but it did much less to wrap up the whole story than I had hoped for. Anyway, that was some nice light reading, solidly entertaining and quite funny in parts, although not much more.

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Juniper SRX100

2011-06-03T10:09:56Z

As mentioned before, IOS is a pain in the neck if you don't use it on a day-to-day basis, hence the wish to replace the Cisco 1712 — there are too many things I would like to do in the configuration, but I hesitate out of fear of messing it up completely.

Beginning of the year I got an SRX100, the smallest of Juniper's "Services Gateways", meaning an access router with Firewall. Shiny! Apart from a serial console port, it simply has 8 Fast Ethernet ports, which can be configured freely, including as one or more switching groups with port-based or tagged VLANs. The default configuration even makes some sense with one port as a WAN link acting as DHCP client for configuration and a switch of the other seven with a DHCP server giving out RFC 1918 addresses, NAT, and some appropriate firewalling.

But that doesn't help me much for my setup, and as this is a whole new world of configuration logic, I haven't got further im my Copious Free Time™ than the online training "Junos as a Second Language". This one is really not bad, but far from covering my special case, of course. So the shiny new box just sits around waiting to be properly configured. :–(

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Travel to Gdansk

2011-06-02T13:32:39Z

A few weeks ago my mother finally did the long-planned journey to show her sons (and their respective wives) the place in Gdansk where she lived as a child in WW II, as well as the traces of german cultural history in Gdansk and in the area. My father, recovering from (fully successful) surgery, was still too weak to come, and the date could not be shifted any more.

my wife, sister-in-law, brother, and mother in the café "Goldwasser" in Gdansk

Besides the historic inner city of Gdansk, or rather what had been rebuilt after the war, we visited the Vistula Spit and the immensely impressive Marienburg castle. See the pictures at smugmug, if you like. (Captions only in German, though.)

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John Allen: Anatomy of Lisp

2011-01-29T14:21:36Z

Another Lisp classic that I have wanted to read for decades. I have only just begun, so I have not much to say about it except that it is out of print and I had to buy it through a used-book merchant and not exactly cheap, and that I hope to find a few things in it that can help me to make my new Lisp interpreter better.

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McCarthy et al.: LISP 1.5 Programmer's Manual

2010-12-19T13:22:04Z

This one I have been wanting to read for ages. When I finally bought it this summer, I was not so intrigued, though. But that came when code for a Lisp interpreter began to pour out of my brain in fall (see http://hic-sunt-lambdas.de/), and the vacation in November was perfect for reading this book.

It takes a bit of getting into it, because the terminology is different from the later established one in some parts. But then there is all that which is so familiar to anyone who loves Lisp. And much more about implementation details than I had hoped for. Not that any of those is really applicable to my own implementation, though, but it has gives me some ideas that I might like to follow.

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Same same, but different - discoveries with the new Macintoy

2010-08-29T12:23:56Z

After two-and-a-half years, the 12" Powerbook G4, which I had bought already used, two years old, began to feel really old. It had probably been a mistake in the first place to buy a used computer from a line that was already obsolete when they built the last models. (On top of that, the CD/DVD drive was already mostly broken when I bought it, but I noticed that too late to give it back or claim compensation from the seller.)

It mostly felt old playing some kinds of videos. DivX and MPEG-4 in larger formats was too much, as well as some flash video stuff from the net. YouTube was fine, but some others, e. g. those from SPIEGEL Online, were not. And as I had not seen the (technical) point in upgrading from OS X 10.4 Tiger to 10.5, the selection of available software had already begun to shrink noticeably.

After the 2010 tax return it was time now for an up-to-date device again. Months ago I had already resolved to buy a MacBook or 13" MacBook Pro. (The bigger ones don't appeal to me, in particular not at their price.) The white plastic MacBook would have been enough with the RAM upgrade, but with the small Pro costing only 60 Euros more than the MacBook with 4 GB RAM (which the Pro already has), it was the Pro. Good choice. It came with OS X 10.6.3 "Snow Leopard" and runs 10.6.4 now after the first update.

As always, the migration to new hardware and OS version, even from the same manufacturer and in the same product line tradition, brings some, let's say, discoveries. "Same same, but different" or even "sometimes happy, sometimes sad."

Software Update has become much more intrusive. With Tiger, it checked for updates in the background and showed its dock icon only when there was something to do and it needed confirmation from the user. Now it shows the dock icon already when it only checks for updates. When it installs software for which a restart is required, it first asks for restart permission (which is okay), but then immediately shuts down everything and only then begins to install the software, which had previously been done in the background.

Only a short while ago, but still with Tiger, I discovered and learned to appreciate Terminal.app's "New Remote Connection" dialog as a fast and convenient way to open an ssh session to another machine. But now, with Snow Leopard, it wants to start ssh connections by default with SSH protocol version 1, which, for good reason, does not work with any of my servers; after each program restart I have to switch that to automatic or version 2. I have not found anything in the preferences (and I do mean Library/Preferences/com.apple.Terminal.plist) or the application bundle that looked like I could change this default. [Thankfully his has been fixed in OS X 10.6.7 -- ssh is now called without any options by default.]

Other than with my 10.4 installation, IPv6 is no longer consistently preferred with some services - telnet, ssh, http. Sometimes IPv4 is used, sometimes IPv6. I have not yet recognized a pattern. This may well be an application issue, but still it is strange.

X11 seems to work completely different from before.

Regardless if X11 is started or not, each Terminal window has a DISPLAY in its environment that contains the pathname a UNIX domain socket (e. g. /tmp/launch-ghLYjm/org.x:0); the socket exists, but is non-functional if X11 is not running. That confused my mechanism of dectecting the existence of an X server; xdpyinfo simply kept blocking on this socket. No fun. Ok, that could be fixed with an only slightly annoying timeout.

When I try to start X11 myself, it doesn't. Or, sometimes it does. But most of the time, some processes start, but nothing happens in terms of a usable X server.

I thought that my .xinitrc and (rather historic) .xserverrc might cause the problem, but moving them to the side has not really improved the situation. Instead, even without me having done anything (except perhaps checking the socket $DISPLAY for aliveness), it tries every few seconds to start up an X server, fails, tries again, ... you get the idea.

The non-functional DISPLAY variable in the environment causes outgoing ssh logins to fail if ForwardX11 is set to yes in ssh configuration, because the remote host tries to connect to the X server at first. Took me a while to find out that this was the reason why Unison failed to connect to another host.

I guess it is intended like this: Some X11 client connects to the socket $DISPLAY, a monitoring process notices this, starts an X server, passes the socket file descriptor to the X server, and lo! X11 applications can be started just like native ones. Clever, if it would only work.

There is something in the system.log, but I cannot make anything of it.

The new Quicktime Player looks awful. All black!

What is this fascination with black, anyway? When I put the dock on the side, where it belongs (IMO), it turns black! With a bit of transparency, yes, but black. That is ugly compared to the thin and airy dock of 10.4 (and predecessors).

A translucent menubar! WTF? At least I can switch this particular idiocy off again.

There seems to be a general trend towards needless design changes. The new dock (if it is on the bottom of the screen) so three-dimensional with a partial reflection of the icons - wow, that is so much eye candy that I want to take the toothbrush to my eyes. (But black?) Is this a "Yes, we can!" attitude, and "Just because we can"? That sucks.

The rounded upper corners of the windows are less rounded now. I can live with that. The amount of roundness taken from there has apparently been applied to the corners of the pull-down and pop-up menus.

The upper menubar corners are no longer rounded at all. Why did they give up one of the most visible design features of the Macintosh since 1984? Are we no longer nice-looking and a bit cute? This seems to be the most needless design change of all, given that the space previously occupied by the rounded corners has not been put to any other good use.

I like the hardware. Only two annoyances here: the glossy screen (I prefer to use the bathroom mirror when I need a shave) and the sharp edges of the case - because this is where my wrists are when I am typing with the laptop on my belly, lying in my bed. And this is at least 97% of the time when I use it. And the edges are really sharp.

The glossy screen does make for a more brilliant display, with a deeper black, yes. (Hum, does that correlate to that obsession with black I seemed to notice earlier?) Apart from the reflections of my face that I could live without, the display is indeed crisp. I like. (Only after having seen the screen of the new iPhone from a very close distance, I say it could use something more like that in terms of resolution.)

I like the wide format as a good compromise. It lets me put the dock on the side (the black dock) and still have it not steal too much from the screen width. There isn't too much height to spare anyway. The display is now better for watching films not in 3:4, small surprise.

I liked the keyboard of the Powerbook more, but this one is better than I expected. I was afraid that the more or less flat keys offer less guidance to the fingers that the more profiled ones of the Powerbook, but it is not as bad, no insecure feeling. The price paid for being able to shave off 2 millimeters (rough estimate) from the height of the keyboard is not too high. I really like the key illumination, although there is more light coming out from under the sides of the keys than through them.

I love the case. It is gorgeous. The rounded corners, the smooth undisturbed matte surfaces, the flat body - wow. It is often said that Apple sells their hardware more due to its design than its technical qualities. Sure, with this kind of design!

Although I have bought the slowest one, this little machine is screamingly fast compared with the G4. Moments where I had to wait a bit with the old Powerbook are now gone. Good.

The automounter seems to work with less hassle now. I once had a working setup with handcrafted mountpoints via Netinfo with 10.4, but that broke at some point, and I couldn't revive it this way or the other. With 10.6, the /net/$SERVER/ thingy works just like that without any setup required. Joy!

The battery lasts long.

In the end, I am quite happy with the new MacBook Pro. The X11 thing is a real annoyance, all others are minor. The new toy is fast and overall a joy to use.

Update 2011-08-12: After fiddling around over several days it turned out that there was (a) an incompatibility with the decades-old ~/.xserverrc and (b) checking for the existence of an X server at $DISPLAY in my ~/.profile kept it from working. Understandably so, considering that is done during the startup of that exact X server. Why X11 initialization starts a login shell -- perhaps to have the environment variables set up properly -- and has a non-empty $PS1 in there I shall probably never know. At least [ -t 0 ] is false, so I can exclude the check for that case.

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Airport Extreme Revisited

2010-08-15T11:15:16Z

"Kleine Sünden bestraft der liebe Gott sofort" (the Lord punishes you for little sins immediately) is a half ironic saying in German. Well, He did in this case. Only five days after calling the IPv6 capabilities of Apple's Airport Extreme "pointless" (see the previous article), my WLAN access point died. After I had tried to switch the speed from "best" to "54 Mbps", it was more or less bricked. No WLAN any more, no reaction at all on the wired interface, not even after an attempted factory reset.

So I had to get a new access point. I was still curious to get my own hands on an Airport Extreme, so I bought one -- not the cheapest choice to fulfill the need of a simple access point, but what the heck.

First I was a bit miffed, because the GUI tool (I'm sorry, Dave, I'm afraid I cannot let you have a web interface) did not want to run on my Powerbook -- OS X 10.4.11 was too old. I had never seen the point to upgrade to 10.5. But to my surprise there was also a version for Windows, which was even less picky about the platform and did not refuse to run with XP.

And lo! There was more to the GUI than I had seen before, namely not only "Node" and "Tunnel" as the IPv6 operation modes, but "Host", "Tunnel", and "Router", which sounds already much better. In the "Tunnel" and "Router" modes, I have an "IPv6 Firewall" tab:

The form to edit the exceptions looks like this:

So, now I have to apologize: The current Airport Extreme does indeed have some degree of usability regarding IPv6, which would be enough for simple home networks except for the missing IPv6 over PPPoE. I haven't tried it yet (as it works only as a simple bridging WLAN access point in my current setup), but that looks much better than I thought only days ago.

(These pictures are not made with Windows, of course. In between I have the new shiny-shiny, which runs OS X 11.6.4, good enough even for the Airport Extreme admin GUI.)

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Airport Extreme's IPv6 capabilities (or non-, rather)

2010-08-06T13:36:08Z

Apple's "Airport Extreme" has been supporting IPv6 for quite a while. So long, in fact, that I thought it might be somthing useful.

Yesterday I took the opportunity of looking at one, or rather, the configuration GUI, in a shop. "Disappointed!", to quote Wanda's brother, is the word. I knew it didn't support IPv6 over PPPoE, okay. But it doesn't support a lot of anything else either. "Tunnel" or "Node" is the first choice, and I don't want tunneling. When I select "Node", I can set the prefix (of which interface?) and the prefix length, and that is it.

That is strange. That is not even barely useable, it is more or less pointless. No per-interface configuration, no firewall, no whatever-you-name-it. Actually I was a bit surprised, as the IPv6 support of the Macs is fine, and I thought they would make their own networking equiment to match that.

[Addition: I think it was a demonstrator of the Airport Extreme administration GUI, perhaps not the real thing. Please see my more-or-less retraction in the next article.]

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To Photograph or Not To Photograph

2010-05-24T13:11:21Z

Since I was 13, I have had a camera and have liked to photograph. My ambition is limited, and my pictures are rarely great, but I quite like a few of them. They do not usually reach beyond the souvenir picture category, but that is fine with me. I cherish reliving past experiences with the help of pictures.

In the recent past I have noticed that there are moments where I do not want to take photos. These are the ones I want to experience fully in the present, without lessening it by even the tiniest amount, without putting something aside for later use.

These may be picturesque moments in the literal sense of the word, like in the last few days walking through an open-air museum of gorgeous old buildings from all corners of Schleswig-Holstein, or a visit in my favourite restaurant (the fabulous Nil in Hamburg), which has not only a beautiful interior, but also food looking as great as it tastes.

But in these moments, I want to see, not photograph; not record, but live.

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Switch to ISP KGT New Media, IPv4 and IPv6

2010-04-25T09:57:36Z

Not quite happy with Titan-DSL's pricing models (older "Business" flat rate not cheap and with one-year cancellation period, newer 25 GB tariff equally expensive, not a flat rate, and still three months cancellation period) and rh-tec (with their promotional 3 GB/mon. IPv6 offering for € 0) not offering IPv4 connectivity suited for pricate customers, I became customer of KGT New Media. Like Titan a smaller player in the business.

KGT offers an IPv4 flat rate for € 11.90, and the same for IPv6. Meaning I pay € 23.80 for both. This is a bit weird, but still an epsilon cheaper than Titan's 25 GB tariff, has a one-month cancellation period, and they are more flexible - I could choose if I wanted to do v4 and v6 in separate PPPoE sessions or in one. (I chose one so I could do it with the same router; to my knowledge for separate sessions you need separate MAC addresses.) That is more flexibility than with Titan, who insisted (only after a while, weirdly) I do both in one session, so I could not do it with two different routers, as I needed then.

Nearly everything seems to work well with KGT. Reverse lookup of the one fixed IPv4 address was set up well inside of two hours after my request; for the delegation of the reverse zone for IPv6 their support person said he'd have to check a few things first. Unfortunately that was on Friday morning, and apparently he didn't get around to setting it up before the weekend. I am not totally happy with that, but as long as we get that sorted out next week, it's still okay with me.

That it took a day to propagate w21.org's new IPv4 address to the world was no one's but my own fault - I was just too stupid to lower the default TTL to 3600 s as I intended (changed the refresh time in the SOA instead; ouch!).

Addendum: Forgot to mention that IPv6 reverse delegation has been working fine for ages now.

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IPv6 home network devices status

2010-04-06T21:52:18Z

[Today this is kind of obsolete since I use the Cisco 1712 for IPv6 now. I find this device not perfect, but it does everything I want. At least it could if I knew how to configure everything.]

As I have a separate ADSL modem, I am interested only in Ethernet-to-Ethernet routers, and I would prefer one with a point-and-click interface. I want it to be able to speak IPv6 over PPPoE on the WAN side, route to more than one /64 network over the LAN (i. e. have two separate interfaces on the inside, or be able to go through another router), and allow WAN access to services on the LAN specified by IPv6 address and port.

Comments are welcome, particularly with newer information or real-life experience, to <ni@jnickelsen.de>.

These are the devices I have some more information about, in no particular order:

DrayTek Vigor 2130: Covers most things. Currently only one /64 on the inside, no DNS or NTP over v6, no RIPng. Otherwise an attractive device for the common SOHO setup. Cool web gui live demo on the web.

Cisco: the (EOLed) 831 is the cheapest Cisco IOS router with IPv6 support; the 871 the cheapest with Fast Ethernet on the WAN side. The 831 is available on eBay for less than EUR 100, the 871 for over EUR 200. Very feature-rich, but IOS is in my eyes too arcane for someone how does not work with it daily. Update: Got a 1712 from eBay; together with shipping and a separately bought PSU about 90 Euros. Works fine and can do everything but the dishes, but see my comment above about IOS. I do not use most of the features because it is really hard work to dig out the correct configuration commands, and if you make a mistake, things may suddenly cease to work.

Cisco SB WRVS4400N: From the former Linksys product line. According to the manual it can speak IPv6 on the WAN interface only through tunnels. WTF?

OpenWRT: this linux-based open source system runs on a variety of hardware platforms. I have it running on a Linksys (now Cisco) WRT54G. It is (in parts) a hassle to set up and it is less well documented and less reliable than I like. I see it only as a temporary solution.

AVM Lab Version: a public beta test firmware for their Fritz!Box 7270. Cannot make LAN services available to the WAN. [Update: in between it can.][Update: in between the IPv6 support is part of the official released product. Three cheers!]

D-Link DIR-825: As I understand the user manual it can have only one flat /64 network on the inside.

Another possibility is to use a general-purpose computer as a router. Linux and *BSD come to mind as possible platforms. PC Engines and Soekris sell small PC-architecture boards designed for this type of use, and some software distributions are made for this purpose (OpenWRT being one of them). But in my experience a commercial router appliance means much less work to set up and operate.

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Moving IPv6 blog posts here

2010-04-06T21:06:54Z

For about three months I have been writing some blog entries about my joys with IPv6 (the "this-century" Internet Protocol) at home on ipv6.w21n.de. But most of the fun is over now that IPv6 works fine for me. So I think I can move the articles here and spare me the effort of maintaining another site.

I will post them under the original dates, so they'll appear in the past here; if you want to find them, look for the tag "ipv6".

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Ben Goldacre: Bad Science

2009-12-16T16:32:12Z

Goldacre is a medical doctor working for the NHS, and he has a column called "Bad Science" in the Guardian and a blog of the same name. This book is, as I understand it, distilled from both with a bit of new material.

Mainly he has a bone to pick with those who influence the public with the pretension of scientific background, be it their own qualifications or the results of "research". He tells us how honest and accurate medical research is done and why it is done this way, then picks others' work to pieces where it is lacking in accuracy or honesty.

I found this quite instructive and interesting, and because he can write, also entertaining. But there are some points where Goldacre loses his humor, and that is where careless or even deceptive dealing with facts costs actual lives.

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Anna-Ev Ustorf: Wir Kinder der Kriegskinder - Die Generation im Schatten des Zweiten Weltkriegs

2009-12-16T16:31:23Z

"We children of the war children -- the generation in the shadow of the second world war" is the translation of the title. Ustorf shows how people whose parents were children in the war or post-war period can still be strongly affected by war traumas passed on by their parents.

I read this because because I was curious if this is an issue for me, too. After all my parents were born 1937 and 1938, and my mother and her family even refugees from East Prussia. But after reading this book I can say that I am apparently unaffected by these transgenerational traumas.

There is this aspect of having no real Heimat, a region where I grew up and am familiar with everything, because my parents moved around a lot when I was a child. But while this is typical for war and refugee traumas to some degree, both my parents' families tended to move around even before the war, so this is unlikely to be a particular consequence of the war in my case.

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Olaf Stapledon: Sirius

2009-12-16T16:30:23Z

Science fiction from the early 1940s. I found this book first in a dumpster in Vienna on my summer trip 1981, and it was probably the first novel that I read in English on my own.

I was quite impressed by the book and wanted to use it as the examination topic for the oral Abitur in case I needed it, but it turned out that the written exam was in line with my previous grades, so I needed no oral. So the teacher gave me back the book, which he had borrowed to prepare himself for the oral. A co-student who was around saw the book, was curious, borrowed it on the spot, and never gave it back. Now, 28 years later, I read the book again.

Sirius is a dog, the crowning result of a scientist's effort to improve the brain capacity of animals. Sirius, with human-like intelligence, is brought up together with the scientist's youngest daughter, which creates a strong bond between these two unequal non-siblings. Sirius grows up to be a very insightful person, is examined in detail by scientists in Oxford, and later makes a career in sheep farming.

Stapledon makes this book very interesting by exploring an immense number of consequences -- philosophical, practical, sexual, social, ethical -- of a dog being so intelligent. And it is entertaining, too.

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R. V. Jones: Most Secret War - British Scientific Intelligence 1939-1945

2009-12-16T16:29:15Z

Jones was the head of scientific intelligence at the british intelligence service during the second world war, and this book is an account of his efforts in that time: anticipating the german efforts in scientific warfare based on intelligence findings, and developing countermeasures. The primary technical areas were bomber guiding systems, radar, and the V1 and V2 weapons.

Much of this is very interesting. His detailed accounts of the internal politics of british intelligence are a bit tiring at times, but maybe this only reflects how he himself has felt about these issues.

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