router

Today I got AT&T Fiber Internet installed at my house, and I thought I'd document a few things I observed during and after the install.

They trenched fiber boxes between pairs of houses in my neighborhood. It seems like they have little fiber hubs for 8 houses in a set, and those little hubs connect back to the main neighborhood box with an 8 or 10-strand cable, directly buried in the ground.

Apparently my street's main run was kinked somewhere, and only one of the strands had full signal, so I'm the lucky winner who signed up first, and I get that fiber until they run a new cable underground :)

I've been running my Internet Monitoring Pi for a year or so, and it's nice to collect data on Internet performance from inside my network.

But my router—currently an ASUS RT-AX86U—also tracks its own metrics for inbound and outbound traffic, among other things:

Sometimes having the raw data from the router that's on the edge of the network can tell a different story than measuring things behind the router. So I want to grab this data and put it into Prometheus.

It's been a busy start to the year on my Raspberry Pi PCIe Devices website. Not only have we finally made some significant progress learning about the BCM2711's PCIe bus (both good and bad), I've also added a few dozen new Raspberry Pi CM4-based boards to the site.

In my YouTube video today, I go through four of them in depth, showing how they're built and what they're used for.

The four projects I cover in depth are:

1. Bigtreetech's Raspberry Pad 5
2. Seeed Studio's reTerminal
3. Waveshare's Dual Ethernet 5G/4G base board
4. Ab-log's RPi4-RTC-PoE DIN rail computer

And there are some other projects I'm watching closely as they journey down the road towards production:

As I start using Raspberry Pis for more and more network routing activities—especially as the Compute Module 4 routers based on Debian, OpenWRT, and VyOS have started appearing—I've been struggling with one particular problem: how can I set routing priorities for network interfaces?

Now, this is a bit of a loaded question. You could dive right into routing tables and start adding and deleting routes from the kernel. You could mess with subnets, modify firewalls, and futz with iptables.

But in my case, my need was simple: I wanted to test the speed of a specific interface, either from one computer to another, or over the Internet (e.g. via speedtest-cli).

The problem is, even if you try limiting an application to a specific IP address (each network interface has its own), the Linux kernel will choose whatever network route it deems the best.

Since I started testing various PCI Express cards on the Raspberry Pi Compute Module 4, I've been excited to see what new kinds of custom networking devices people would come up with.

Well, after months of delays due to part shortages, both DFRobot and Seeed Studios have come out with their 2-port Gigabit router board designs, and I was happy to receive a sample of each for testing:

The boards are tiny, and even with the Compute Module 4 installed, they are incredibly small—take a look at the entire assembled DFRobot unit, complete with a Raspberry Pi attached:

I needed a very basic 'Internet sharing' router setup with one of my Raspberry Pis, and I thought I'd document the setup process here in case I need to do it again.

I should note that for more complex use cases, or where you really need to worry about security and performance, you should use something like OpenWRT, pfSense, or VyOS—or just buy a decent out-of-the-box router!

But I needed a super-simple router setup for some testing (seriously... look at the picture—the thing's about to fall off my desk!), and I had two network interfaces on a Raspberry Pi running the 64-bit build of Raspberry Pi OS. These instructions work on that OS, as well as Debian, Ubuntu, and derivative distros.

If you've had an AirPort Extreme for a while, and recently (within the past year or two) had it go missing from your network (when you open AirPort Utility you get 'Device Not Found'), there's a good chance you ran into the same issue I did. Basically, everything was running great, then one day around August 2016, my Extreme disappeared from the network—even though it was routing Internet traffic for all the devices in my house just as good as ever!

The fix?

1. Open AirPort utility (it will likely show "Device Not Found").
2. Unplug your AirPort Extreme, and wait 10 seconds.
3. Plug it back in, and connect to the WiFi network as soon as possible, then immediately go to the AirPort Utility.
4. The AirPort should appear and be manageable (by clicking on it) for a brief period—quickly click on it, click Edit, then clear out any Apple IDs in the 'Back to My Mac' section.

My wife and I needed an extra dresser to keep up with the growing family (third baby is on the way in a few months!), and since we would rather buy things that last—but not buy new if we can save a bundle of money—we bought a used wood dresser on Craigslist:

First lesson: always inspect every last bit of furniture before loading it up and hauling it away! Most of the rails were in not-great condition, and the guides on the drawers weren't in great shape either:

We decided to make the best of the situation and make as good a repair as possible, resulting in much improved (like new!) rails:

I spent the greater part of this afternoon trying to get my AirPort Express to connect to the Internet and share an IP address using a Motorola SB5101 Cable modem (with Charter Internet)... and since the solution was so simple and annoyingly stupid, I thought I'd post it here, for my reference and for anyone else spending an afternoon thinking his AirPort Express is dead.

As it turns out, the cable modem (this one, and likely many others) will only remember the MAC address of the first device it recognized when you last power cycled the modem.

When the Internet went down at my condo yesterday, I turned off my cable modem, plugged my Mac straight into it, turned the modem on, and use the internet via this direct connection for a while. When I plugged the AirPort Express back into the SB5101, I just got a flashing yellow (amber) light, and in the Airport Utility, a notice that the 'Internet Connection wasn't working'.