Ethernet port not working anymore

Started by WimRoose, September 19, 2016, 11:03:49 pm

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Hi all

I've already searched the forum, but found nothing about an ethernet port on an A20 Micro suddenly refusing duty. Was running Debian Jessie, uptime > 100 days, but last week, on the end of an apt-get update, ethernet port stopped working. Port is recognized by OS, but doesn't receive any dhcp offers anymore. And is certainly not a network issue, neither a software thing: same sdcard in another board: everything ok - same board with newly written SD: also works.

Anyone a clue? Never had broken ethernet port before. Shall I try soldering a new one?




Same (likewise) here: I switched from wheezy from Jessie this week and the ethernet port (eth0) stopped working:
I have been searching for 2 days now and so far I get the error: 'No DHCPOFFERS received' - obviously, I am trying to use DHCP.
I checked the cable, the connection and the DHCP server and they are all ok and my hypothesis is that the DHCPDISCOVER is never sent or maybe not in a correct format.

Any help appreciated.

Freek (NEWBY)


A software change stopped it working?  Go back to the working software.  Report the fault to the appropriate place(s) or it will stay broken.



Hi John,

Thank you for your reply - it encouraged me to take the extra step to try to reproduce the behaviour and indeed: with success and I will file a bug report 'in the appropriate place' whereever that may be, but I guess I will be able to figure that out my self (in the true 'rtfm'-spirit).



Ok, I guess I worked it out by myself: there does not seem to be a bugtracker of some kind, just a procedure for 'technical support help', see:

So, here is my 'technical support help request'/bug report:

Title: Jessie breaks ethernet port

Entry criteria:
1. one A20-OLinuXIno-LIME2 board.
2. One sdcard with a 'Wheezy' image (
3. One sdcard with a 'Jessie' image (

Steps to reproduce the bug:
1. Connect the board's ethernet card with a ethernet cross cable with a laptop.
2. Boot the board with the Wheezy sdcard.
3. Follow the instructions in the user's guide to setup a SSH-connection via the Ethernet connector over the static IP address to verify the integrity of the card.
4. Power off the board.
5. Boot the board with the Jessie sdcard.
6. Remove the '#' in front of the line '#auto eth0' in /etc/network/interfaces.
7. Reboot the board.

Observed behaviour:
8. It is not possible to establish a SSH connection via the Ethernet connector over the static IP address.

'ip route show' returns: dev eth0 proto kernel scope link src dev usb0 proto kernel scope link src

Expected behaviour:
8. It is possible to establish a SSH connection via the Ethernet connector over the static IP address.

Next step: I will mail this bug report using the SUPPORT link on the bottom of our home page.


AFAIK none of the software was developed by and none is supported by Olimex.  It's Linux, isn't it....  (And there are maintainers etc.)

Still, maybe they'll jump in but don't be surprised if not.



Thank you for sharing your point of view.
I am not sure as to what to do next, but maybe it's best to wait and see whether olimex reacts and what their reaction is. Meantime I guess I could poke the Debian community and see whether they had the same experience on other processor architectures.

To be continued.


You might be able to modify the driver to show if it is hanging or contact its maintainer or the linux-sunxi ML about it.

I suspect Debian will say it's specific to the AW chip(s) / driver(s) or will want evidence that's not the case.



Hi John,

Thank you for yet another helpful hint.
I will check the linux-sunxi to find the driver and see whether I can reproduce the behaviour by updating it.

To be continued,


September 27, 2016, 11:19:36 am #9 Last Edit: September 27, 2016, 11:22:45 am by JohnS
If you pull the Linux kernel source and build it then you already have the driver etc and can also make changes to try to see what's happening.

The ML guys are busy but friendly and helpful so if you get as far as being ready to make changes and are stuck ask them what sorts of things to try.  They'll expect you to have had a go at building and running kernels so at least have a go :)

It's all "fairly easy" (no, really, it is!).  You just need plenty of disk space and wait a while for the first build as it has to compile a LOT of code.  Next builds are much faster.

Tons of info on about how to build u-boot as well as kernel, how things boot and so on.

Olimex have put examples of how to build kernels etc on their wordpress / wiki, too.  Essentially it's the same for all processors with a few changes.

Because gcc can cross-compile you can do it all on a fast PC even though the result would not run on the PC then write it to such as an SD card and boot it on the A20 board.