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Registered: ‎10-14-2019

Unable to ping LWIP echo server from Ubuntu

Hi guys.

I am unable to successfully connect to the example LWIP echo server provided with Vitis, I suspect the problem is at the host (ubuntu) side. I am using:
- Zedboard
- Vitis 2019.2
- Ubuntu 18.04.1

When running the application and connecting my desktop comuputer to the RJ45 port on the Zedboard, I get the following output over UART:

-----lwIP TCP echo server ------

TCP packets sent to port 6001 will be echoed back

Start PHY autonegotiation
Waiting for PHY to complete autonegotiation.
autonegotiation complete
link speed for phy address 0: 100
DHCP Timeout
Configuring default IP of
Board IP:
Netmask :
Gateway :
@TCP echo server started @ port 7

The ZedBoard is connected to the second out of two network interfaces on my Delll Precision 5820. When I monitor this port with Wireshark I detect no traffic when trying to ping the IP address. In fact the ping requests are sent over the first network interface which is connected to the internet. I have a attached a print screen of the traffic recorded at the port connected to the ZedBoard as well as the wireshark dump. The only messages I can see from Zedboard are a few "DHCP Discover" packets. So there is no way that my desktop computer can know that belongs to the MAC addr of Zedboard and is attached to that interface.

I have searched around alot and gone through many discussions about LWIP example not working, but none of them covers my experience here. Any suggestions?

Screenshot from 2020-09-30 13-09-30.png
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Registered: ‎10-14-2019

Another update.

My desktop has 2 ethernet interfaces, en0 is connected to internet and enp2s0 is connected directly to the Zedboard. When just doing something like:
"ping" it is sent out on en0 and gets no reply.

When I instead do "ping -I enp2s0" it is sent over the right interface and I pick it up in Wireshark. But I get no response from the Zedboard. It gets even wierder. When I try to connect a Raspberry Pi to the Zedboard I am able to do a ping and get a response back. When I check out the packets on Wireshark they are completely identical. It is a mystery to me what is the problem here. I really appreciate any help I can get here.

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