I've been working on debugging KSZ8081RNB Ethernet chip for three weeks now and still, I can't find where the problem is.

First of all, the board I am working on is including an IMX6UL processor and some chips to drive some amplifiers, bluetooth interface... The current design is inspired from the Evaluation board (EVK) from NXP. I have a configuration around my KSZ8081RNB which is the same on my board and on the EVK. Plus the wiring is equal between the IMX6UL and the KSZ on the two boards.

I have made and upload a U-BOOT working on the evk. It include the configuration to interface with the ethernet chip. When I use a ping command, everything works great... I can see on my server using wireshark that I have ARP and ICMP exchange. Every packets are coming in and out to the IMX6UL (I have made some traces to be sure)

Now, back to troubles :)

On my version of the board, I have upload the same code and there are the symptoms: -some of the packets (ARP and ICMP) are entering without problem: when I launch the network loop and ping from the outside world, I can see the packets entering correcly (I cheked it in the IMX6UL) BUT when come the time to give the response, ARP and ICMP packet get blocked by something.. Sometimes the packets gets outside and are read by the server sometimes they wont.

What I have done: I check power on the KSZ, the type of RJ45 connector, the configuration MDIO of the KSZ, the 50MHz clock and it's jitter. Nothing seems to explain the irregularity of the ping process...

Got some ideas? Comments? Need some more informations?

  • \$\begingroup\$ Where does your board get its MAC address from? \$\endgroup\$
    – Steve G
    Aug 1 '16 at 11:15
  • \$\begingroup\$ I came from U-boot environment, and I check my ARP packets it 's the good one. \$\endgroup\$
    – Joe Lara
    Aug 1 '16 at 13:01

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