On 2026-03-16, Alex Frolkin <[email protected]> wrote: > Hi all, > > Can anybody recommend a 4G USB dongle that works with OpenBSD, ideally > without any kernel fiddling (although I am open to this if necessary)? > > The umsm(4) manpage claims to support the Huawei E3372, but the reality > with this model is complicated. I have a pair of E3372h-153 dongles, > one with its original Hi-link firmware, one reflashed to stick firmware. > > With Hi-link firmware, I get a USB serial port that I can issue AT > commands on, but when I say "ATD*99#", it says "CONNECT" and then > nothing happens. I'm pretty sure that this is because Hi-link firmware > does not support PPP mode at all. > > With stick firmware, the device is not supported at all. On a different > OS, I get two serial ports and a CDC NCM device, and I can connect by > issuing an AT^NDISDUP command on one of the serial ports, and DHCP-ing > on the NCM interface. Support for this mode can perhaps be easily added > to umsm(4), but OpenBSD lacks support for CDC NCM, and umsm(4) support > wouldn't be much use without that.
NCM is more of an ethernet-type of interface rather than serial-port-like so would be a different driver than umsm. dlg@ has a start at a driver: https://marc.info/?l=openbsd-tech&m=174947099422896&w=2 > Does anyone have experience with the E3372 on OpenBSD and has managed to > make it work, at least in some mode? Or is there another dongle that > "just works" with OpenBSD? Not sure what the Huawei I had working was (it was a long time ago) but there are a lot of differences between firmware builds and modes within a particular build that you might not be able to replicate a success that someone else had. E3372 is on the list in umsm(4) so somebody will have had at least one version working.. Sometimes it can be worth looking at how things are setup for a device with modeswitch on Linux and seeing if it can be adapted to match the kernel-side device matching and mode switching in OpenBSD. Generally the best currently supported options are devices using umb(4). But as usual finding devices and firmware and the right mode can be tricky.
