14.2.13. Ethernet Does Not Work
- Question:
- Ethernet does not work on my board.
- Answer:
- Maybe you forgot to set a MAC address?
Check if the
"ethaddr"
environment variable is defined, and if it has a sane value. If there are more than one Ethernet interfaces on your board, you may also have to check the MAC addresses for these, i. e. check the"eth1addr"
,"eth2addr"
, etc. variables, too.
- Question:
- 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? | |||
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