Skip to main content.

14.2.13. Ethernet Does Not Work

Question:
Ethernet does not work on my board. I have configured a MAC address of 01:02:03:04:05:06, and I can see that an ARP packet is sent by U-Boot, and that an ARP reply is sent by the server, but U-Boot never receives any packets. What's wrong?

Answer:
You have chosen a MAC address which, according to the ANSI/IEEE 802-1990 standard, has the multicast bit set. Under normal conditions a network interface discards such packets, and this is what U-Boot is doing. This is not a bug, but correct behaviour.

Please use only valid MAC addresses that were assigned to you.

For bring-up testing in the lab you can also use so-called locally administered ethernet addresses. These are addresses that have the 2nd LSB in the most significant byte of MAC address set. The gen_eth_addr tool that comes with U-Boot (see "tools/gen_eth_addr" ) can be used to generate random addresses from this pool.
14.2.12. Erasing Flash Fails 1. Abstract 14.2.14. Where Can I Get a Valid MAC Address from?
Prev Home Next