So, I have a spare computer out in my shop which I have used to host various small bits of networking. Previously I used it to host reports from my solar powered WSPR beacon. I thought it might be nice to make it available on the AREDN network as well.

This machine uses “conceptron” as its hostname, and because I didn’t have a convenient way to get a cable pulled out there, it connects to my home wireless network via a small TP-LINK USB wireless dongle. I decided to plug the dongle that I was using to provide a link to my AREDN nodes (the GL.iNet GLUSB150) into that node to also make it available on the via the AREDN network. I plugged it in, configured the network, and was easily able to access it via the AREDN network.

But I was no longer able to access the node via the conventional Internet.

The problem boiled down to a simple one: the GLUSB-150 looks like an ethernet device. When its plugged in, it is automatically recognized by my Linux box, and it configures a default path through it. Also, because it is a wired connection, it has a higher metric value than the wireless connection. This means that by default, traffic goes out over the AREDN network, rather than the conventional network.

There is a program that you can use to adjust the metric value a given interface. I lowered the new “Ethernet” interface, and things began to behave as expected.

I still have to figure out how to make sure this happens by default upon reboots.

Addendum: Actually, it doesn’t appear that this works flawlessly. It appears to work from within my home network, but not for links outside. I’ll have to think about it some more.