router

Two Tiny Dual-Gigabit Raspberry Pi CM4 Routers

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:

DFRobot and Seeed Studios Router Boards with Dual Gigabit Ethernet

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:

DFRobot CM4 IoT Router Board with Raspberry Pi CM4 and Quarter

Setting up a Raspberry Pi with 2 Network Interfaces as a very simple router

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!

Seeed Studios Raspberry Pi Compute Module 4 Router Board

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.

AirPort Extreme showing 'Device Not Found'? Here's a fix

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.

AirPort Extreme Back to My Mac Apple ID listing

Reviving an old dresser by rebuilding the wooden drawer rails

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:

Craigslist wood dresser

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:

Craigslist dresser with old broken wood drawer rail guide

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

AirPort Express - Flashing Yellow Light, Not Getting DHCP Address from Cable Modem

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'.