Arnt Gulbrandsen
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IPv4, IPv6 and reliability

I didn't expect that this would be common enough to see it myself:

What it means is that IPv4 has become (or is becoming?) less reliable than IPv6 as a transport. The web service (a nice professionally run place) detects that my NAT gateway has tried to do something nasty, and blocks some functions from its IPv4 address. Thousands of people use that NAT gateway, because my ISP has more customers than IPv4 addresses and puts all of us behind one IPv4 NAT gateway.

IPv6 doesn't have this problem — each customer gets a unique IPv6 prefix so only the malevolent customer is blocked, the block won't affect thousands of bystanders.

Multiple APs and SSIDs with Mikrotik RouterOS 7

I replaced my old Mikrotik hardware recently. The oldest AP was almost fifteen years old, and Mikrotik still delivered OS upgrades for it: Fantastic. I'm a fan.

But I replaced it. My new setup involves three APs (my home has a very difficult layout) and four SSIDs. Setting it up was a little too tricky, RouterOS 7.14 is substantially different from both of the older approaches (capsman and interface wifiwave2). Mikrotik's documentation mostly explains it, this posting explains it differently. […More…]

Jelly Max

I backed the Jelly Max on Kickstarter as soon as it was announced. It's larger than the old Jelly phones, which I liked but ultimately stopped using.

I wrote about the Jelly 2 that it fits in every pocket I have, even in my tightest jeans, it runs the apps I need, and if it makes me spend less time on Twitter, that's fine. Fine, all true, all correct. Why did I eventually switch back to my old Xperia XZ1 Compact?

Part of the story is that the nice guys who build LineageOS for the xz1c kept providing upgrades (here's Android 14), another part is that the bezels on the Jelly 2 ought to be narrower, a third part is that I couldn't find a good phone holder for my bike. I had to switch from the Jelly 2 to the xz1c before a weeklong bicycle trip and… never switched back. […More…]

IPv6-only mail

Following an unfortunate sequence of events, my mail server is currently reachable only via IPv6. It took me a few days to even notice the lack of IPv4.

IPv4 connectivity should be back in a day or two. We fixed the root problem last night.

What I learned from this involuntary experiment: Lack of IPv4 access for a mail server is real problem in 2024, it's something that has to be fixed, but it's a surprisingly small problem.

A set of cufflinks

Last week I had a set of cufflinks made. What luxury.

They were made out of four old Algerian coins. The silversmith (Geldschneider in Dresden) had used the outer parts of the coins to make rings, and what you see is the remaining inner parts, burnished and polished.

Note the two numbers on the coin in front: That coin was made in 1960 AD written with Latin digits, and in 1380 written with Arabic digits. If they look similar, that's because they are. The area from Morocco to Lebanon uses Arabic digits (that is, 0123). Further east they mostly use ٠١٢٣ instead of 0123, although it's mixed there as well.

Why is the epoch 580, though? EDIT: The epoch is 622AD, not 580. The coin was made 1380 lunar years after the Hijrah, or 1337/1338 solar years.