Arnt Gulbrandsen
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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.

Each AP is a router, and forwards incoming packets. This includes packets that arrive from a wifi station such as a laptop.

Each AP makes its own radios available as interfaces on the main AP. The main AP sends packets using these interfaces, but it does not receive.

The APs must be switched together, not routed together. Many devices assume that all APs provide access to the same DHCP leases. This effectively requires that a broadcast packet sent to any AP reaches the same DHCP server. I think most configurations will involve one VLAN per SSID, and bridge interfaces.

The only sensible way to combine VLANs and a bridge is now to set physical interfaces as ports, and then configure which VIDs can be received and sent on each physical interface. If you want to assign an IP address to a particular VID, you use interface vlan add to create an interface with the right VID on the bridge, and assign the address to the vlan interface.

Bridges are separately configured on each AP. interface wifi configures the wifi interfaces of satellite APs, but it does not configure bridge interfaces.

That's it. That's all you really need to understand.

In my case, the main Mikrotik AP is called chanel, and one of the others is called miu-miu. Both serve an SSID called tralala. I have a laptop called attovax that's currently connected to miu-miu.

A packet from attovax to the general internet goes from attovax to miu-miu, which sees that its wlan2 interface is connected to a bridge with VID 7. That bridge is also connected to an ethernet cable for which VID 7 is enabled, and after passing through an ethernet switch, the packet arrives at my border router. Note that this packet does not pass through chanel.

Return traffic from the internet arrives at chanel, which routes it to its corresponding bridge and assigns it VID 7. Chanel has an interface called miu-miu2, which is also connected to the same bridge and has VID 7. The packet goes out over miu-miu2, which is really a tunnel, and is physically sent by miu-miu's radio. Note that this packet does pass through chanel, but does not pass through miu-miu's bridge.

Simple? At least it's understandable, given the points above.

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.

Visual fashion in user interfaces

User interfaces change with the times. A 3½" diskette as an icon in apps may now be obscure because hardly anyone has seen the physical object in 25 years, and applications based on swiping have functional differences from older mouse- or keyboard-based ones. That isn't what I have in mind today. Apps that swipe may be fashionable, but the swiping is at least partly a matter of function. This post is about pure visual fashion — choosing particular kinds of shapes, sizes, fonts, colours, textures and animations instead of other kinds.

I'll discuss a modern, stylish photo from a web site that's 100% about popular fashion, and then a screenshot of a modern, stylish android app. By popular fashion I mean fashion that comes from the vox populi rather than from designers in Paris or the Vogue editors. Instagram's click-fuelled feedback loop produces that, I think, and the photo below is arch-instagram. The app is a high-quality app from a small company. They couldn't be more different, and what I'll describe is their similarity. […More…]

Saudi science fiction

This is what the airport in Dubai showed me on the landing page when I connected to the WLAN there:

I've never been to Dubai, the city. Does it look like that? Maybe the photo borrows a great deal from the style of old science fiction paperback covers, or maybe the city planners in Dubai really like Don Dixon's SF covers and are trying to build a future city in that style. If so, I think they should reread Crash, and maybe High-Rise by J. G. Ballard, an author of fine science fiction. […More…]