Ethernet troubles with 0.6 and firmware 1.20

Apologies if this was answered elsewhere, but I can't get my Duet 0.6 to play nicely with firmware / webcontrol 1.20.

It's been powered on for over a year, and I've done updates over the web interface, and everything was working fine with 1.20/1.20.
But after a power cycle, it would sit in a constant reset loop.

I managed to narrow it down to the Ethernet interface, because if I unplug that it will come up and I can communicate over USB.
Plugging in the Ethernet after booting it would reveal a rolling "Network down" update and it would never connect.

Dropping back to firmware 1.18.2 worked. Webcontrol 1.20 would bring up a browser interface (no temperature status for hotend or bed).
So I've gone back to firmware 1.18.2 and webcontrol 1.15a and that is working ok.
I haven't tried updating again though.

Is the 0.6 support gone, or going away, for newer firmware?
If not, has anyone else encountered this?

I have one other report of a similar problem, but I am unable to reproduce it. The fault seems to lie in the DHCP client code. Setting a static IP address in the M552 command resolved it for the other user.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanks for getting back to me. I'll probably stick with 1.18.2 on that printer, but here are some more data points if it's helpful:

- My router recognized the MAC address and set aside an IP address while it was in its reset loop. I couldn't access it in the browser.

- When I plugged Ethernet in after booting, starting the "Network down" cycle, the router still set aside the IP address, but M552 returned IP address of 0.0.0.0.

- Setting the static IP address did not fix my problem--M552 would return the address I assigned, but I couldn't access it in the browser.

- Changing Ethernet switches was unsuccessful, as was using a crossover cable.

- Router: Mikrotik, running RouterOS

What's more useful is the software reset report from M122 after you have interrupted the reset loop by unplugging the Ethernet cable.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].