On Sun, Oct 19, 2025 at 13:04:26 -0500, John Hasler wrote:
> I'm still unclear as to what the problem is.
As far as I can tell by piecing all the guesses and hints together,
the problem appears to be something like:
My Internet service provider has given me a router which connects
to my computer via USB instead of ethernet.
The device acts like an ethernet over USB network interface.
Debian recognizes it. It's working fine.
However, for reasons I can't say out loud, I want to know how much
bandwidth I'm using per month.
I tried vnstat, and it would seem to do what I want, but there's a
small problem: the USB device's MAC address changes every time I
blink. So, the "predictable" interface name keeps changing.
Therefore, the vnstat database has separate totals for every single
interface name that it has ever had.
I want all of the USB interface data to be totaled up and reported
as a single number.
So, the solution approaches would appear to be:
1) Scrap the device and use something that doesn't suck.
2) Tell the device to stop changing its MAC address.
3) Connect to the device via ethernet or wifi instead of USB.
4) Configure systemd.link(5) to tell Debian to assign the same name to
the interface even though the MAC address is changing.
5) Add up all the numbers from vnstat to get a total.
Any or all of these might be viable, depending on information that has
not been provided to us.
