ipv6 address showing up but not ipv4 (Eclypse-Z7 Linux Demo)

[davwamai]

I am following the ZMOD ADC Linux demo on the Eclypse Z7 resources page(https://digilent.com/reference/programmable-logic/eclypse-z7/demos/zmod-scope). 

I am using Ubuntu 18.04 on my host machine and SDK 19.1 as per the instructions in the demo. 

I am using putty to connect to my board over ttyUSB1 in PROG and an ethernet cable between the board and my host machine. The ethernet cable labeled eth0 is showing up on both my board and my host machine when calling 'ip a'

For step 6, when calling 'ip a' in putty, only the ipv6/inet6 address corresponding to eth0 shows up, and not inet/ipv4. I am required to use only ipv4 as per the instructions in the demo. 

 

I have tried modifying the /etc/network/interfaces file on my host machine and my board, using the ipv6 address in place of the ipv4 address, rebooting the host machine and board separately, removing and reestablishing eth0 with 'sudo dhclient -r eth0' and 'sudo dhclient eth0', resorting to other documented solutions to similar problems on google, and so far nothing has worked. 

attached are screenshots of my host machine's interfaces file, the output of 'ip a' on the board, and the output of 'ip a' on my host machine. 

I am not sure how to resolve this issue, any help would be greatly appreciated. 

[JColvin]

Hi @davwamai,

I am taking a look into this; I will let you know what I learn.

Thanks,
JColvin

[JColvin]

HI @davwamai,

I tested out the Linux demo (ZmodADC1410_Demo_Linux) on SDK 2019.1 on my Windows 10 machine and was able to see and use the IPv4 address when the Eclypse Z7 and my host computer were connected to the local router at the work office while following the same instructions. I verified this on both the v0.3 and v0.2 pre-release images that were available on the Github releases page: https://github.com/Digilent/Eclypse-Z7/releases.

You mentioned that you have the Ethernet cable between the Eclypse and the host computer; I suspect that this is the issue at hand as neither the Eclypse nor host computer would have an IP address assigned to them (since neither of them are DCHP servers). I verified this for myself since as far as I can tell, it does not appear that the Eclypse demo does not assign it's own IPv4 address to itself if one is not automatically assigned to it (doesn't matter if you manually assign an IPv4 address to your own Ethernet port on your host machine as that does not affect the Eclypse).

You can assign the Eclypse it's own IP address by running the following command in the serial terminal:

Quote

sudo ip addr <desired_ip_address> dev eth0

and then assign the Ethernet port your own host system to have its own IP address on the same subnet (first three number groups of the IP address). Naturally you'll want to make sure that whatever IP address you assign to both systems to not be conflicting with anything else on the network.

If you want to switch the Eclypse back to automatically receive an IP address from a router, you can either power cycle the board or running:
 

Quote

sudo ip addr flush dev eth0

Let me know if you have any questions.

Thanks,
JColvin