Skip to main content.
Navigation:
DENX
>
DULG
>
EthernetDoesNotWork
Translations:
Edit
|
Attach
|
Raw
|
Ref-By
|
Printable
|
More
DULG
Sections of this site:
DENX Home
|
DULG
|
ELDK-5
|
Know
|
Training
|
U-Boot
|
U-Bootdoc
Topics
DULG Home
BoardSelect
Manual
FAQ
Application Notes
Changes
Index
List of pages in DULG
Search
%SECTION0{name=EthernetDoesNotWork}% 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 <filename>01:02:03:04:05:06</filename>, 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. <p></p> Please use only valid MAC addresses that were assigned to you. <p></p> 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