General Questions

Yesterday my old VIA EPIA-ML just gave up, so I went with a nice little Atom board.
I thought the clever way would be to plug the USB Key that I run m0n0wall from into my PC, mount it,
and change the config file so it contain the new interface name.
With the EPIA, my LAN was vr0, now it has to be rg0.
Apparently there was just one instance of vr0, so I replaced it, unmounted the key, plugged it into the atom board and had it boot.
To my surprise, I didn't get an IP address assigned, but the PC picked up an IPv6 address from the RAs.
I checked the webgui via v6 and the DHCP logs told me "dhcpd: rg0: not found"
The other interface names all stayed the same, since I carried over the PCI NIC. DHCP works just fine on them, apparently.
So why is it that dhcpd doesn't want to work on rg0?
ifconfig on exec.php shows that rg0 is up and running. Did I miss something here?

Since I don't have a good old VGA cable at hand, I cannot run a fresh install and re-assign all the interfaces "the proper way"

Just a wild guess: perhaps a space or funky/invisible character around "rg0" in your edited config.xml?

Good idea, I just checked that, but no.
BUT in the meantime I found out that the mentioned error message is the dhcpd author's way of saying "this interface doesn't have an IP address assigned" - and indeed, there was no IPv4 address on the interface, just IPv6. I looked through the syslog but didn't see anything fancy there, so I manually assigned the configured address using ifconfig, restarted the dhcpd and it worked...

What I did notice after restarting the machine a couple of times is that after it finished booting (well I assume it's finished at this point, because the USB key's LED stops flashing), the orange LED at the NIC port doesn't light up for another 10 seconds at least, while the green LED already starts blinking. Don't know if this is related in any way, but it seems odd. I'm used to one of the LEDs being the "link up" LED that would practically light up as soon as you power on the machine (if the network cable is plugged in)... But it may just be an oddity of this particular board/chipset and not really a bug.

I'll fetch a VGA cable early next week and do a clean test install to figure this thing out.

Unfortunately I could not investigate any further; turned out something else was broken (apparently the USB key), so I returned the atom board, switched to using a HDD temporarily, and my EPIA-ML is working fine again.
The Atom board was a "Int Essential  D410PT + Atom D410", just for the record.