Docs to enable running OpenWrt on a managed switch

Greetings

I have been following the thread over in the 'Dev' section (OpenWRT on a managed switch).

This is not a complaint but there aren't any clear docs (like for most of everything else here).

So what can I (hopefully we) do to help the dev group that has been, IMO anyway, successful at giving us this new option?

Please advise.

rtl838x is rather well supported at this time (at least for the devices that already have binary images available in the realtek target), it's working pretty nicely. However you should be comfortable to attach a serial console (3.3V!) and don't feel scared about loading and booting an initramfs image over tftp, before flashing the sysupgrade image from there. If any of the above scares you, it's probably not a good idea for now.

The bigger issue complex is not realtek specific per se, but a consequence of the current state of DSA support in OpenWrt right now (not just affecting realtek, but also mvebu and the various ramips targets - as well as ipq806x within short time). While netifd has learned about the basics (and a bit more) by now, luci integration is still missing (and while there is a pull request adding a prototype, it's not merged yet). If you want to exploit the features and capabilities of L2 managed switches to their full extent and set up multiple VLANs, you will have to be able to collect information based on the sparse documentation and sources for the time being - furthermore it would be advantageous to be familiar with iproute2.

Given that both DSA support in OpenWrt and the realtek target are still rather new, you should be rather flexible, willing to learn and able to work on it on your own, without requiring lots of documentation or pretty webinterfaces for now. There are bound to be changes (e.g. the current default setup setting up the management interface on port 1 only via VID100), but the hardware support itself is rather nice and stable already.

If you are familiar with OpenWrt and not afraid of using the cli or to edit configuration files, this could be a rather rewarding learning experience.

2 Likes

Asking to make sure I'm understanding - - - -

A serial console - - - - that can be connecting an RS232 cable to another m/c and setting up a terminal on the second machine to 'talk' to the subject machine - - - - yes?

Is it something more in this instance?

(That used to be a printer connection technique once upon a time - - - grin!)

yes and NO!
RS232C as in often found on older computers is specified for up to +/- 25V, which would permanently fry the router/ switch inmediately.
Yes, as it's still the same protocol and usage, just at 3.3V, as provided by 3.3V based usb2serial adapters (available for 1-5 bucks, depending on how long you want to wait for the shipping, from China or more locally).

Do not get any old printer gear or db-9/ db-25 connectors near it (25V).

The wiki has more details about this and its usage.

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just for safety reasons, I'll throw in the term cp2102.