I have a fresh install of OpenWRT on a NetGear GS308T; it has no dedicated WAN port. The default configuration seems to have the LAN and WAN devices backwards: all of the ports are in the WAN, and the first port is alone in the LAN.
I've had a look around the forums, but I don't think this question has been answered before in a way that makes sense for this setup:
Thanks for the link, though I had indeed read that; it looks like the default configuration is just completely broken (WAN ports bridged with LAN ports, admin VLAN on the WAN switch).
I still don't see how to get ssh and LUCI listening on the default (untagged) LAN side, unless I missed something in the tutorial/forums.
I'll post the answer when I can get a working configuration. Meanwhile, it's not mounting the overlay FS, despite flashing the squashfs-sysupgrade image. I'll open a different thread for that.
Note for anyone looking at this thread: the stripped-down config on the GS108T page probably works, but doesn't explain how to SSH and LUCI are configured to read from the LAN.
This should do the work. lan1 port is assigned to vlan1, which is wan. The rest of the ports are assigned to vlan100 untagged, which is the lan.
Just in case something doesn't work as expected, be prepared to reset the device to defaults or login with serial/failsafe.