can we change MAC Address of ARM9 based LPC3250 board?

Hi,
I am working on ARM9 based LPC3250 board with kernel version 2.6.34. I have installed SNMPD on my board (target) and i want to communicate with another same board (HOST) using snmp. MAC addresses of both board are same.
I have tried to change MAC address of one board for proper communication in U-BOOT code but it is not reflected.
can we change it or not? If we can then how?
Please give me reply.

Thanks & Regards,
MOHAMMAD BIYABANI.

I am not very familiar with the embedded LPC3250 board. However, I will try to provide some help.

The Ethernet MAC address is set using a kernel parameter named "ea_ethaddr". There may have been a change in kernel 2.6.34 that requires you to use the a kernel parameter named "ethaddr".

Here is a link to a post that may be helpful.

Problem using 2.6.34 in EA 3250

In the instructions found in the "Getting Started With Linux on the LPC3250 OEM Board" manual, you may have to change "ea_ethaddr=$(ethaddr)" to "ethaddr=$(ethaddr)".

If that does not solve your problem I suggest that you look at the documentation for the Embedded Artists Ethernet driver for Linux that is used for the LPC3250 board. That should explain the driver parameters including how to set the MAC address.

Thanks for your reply,

I changed the MAC address using setenv macaddress command. But i have another doubt that

In my two lpc3250 based boards all requirements to boot the board like u-boot,kernel and Root file system are loaded and i want to know
how to communicate with two LPC3250 boards using ethernet.

Actually i have tried with below procedure with ip addressses and gateways(changed in u-boot)

1. board 1
ip addr 192.168.1.19
gateway 192.168.1.101

board 2
ip addr 192.168.1.101
gateway 192.168.1.19


2. board 1
ip addr 192.168.1.19
gateway 192.168.1.10

board 2
ip addr 192.168.1.101
gateway 192.168.1.10

But i cant able to perform ping operation. Please give reply if anybody gone through this or know about this?


Thanks & Regards,
MOHAMMAD BIYABANI.

The gateway address is not needed to "ping" from a computer located on the same network with the two boards.

If you want to communicate outside your network then the gateway address should be the address of a router or internet gateway. The gateway address should not be the same as either embedded board.

After you ping each board you can tell how the Ethernet MAC address was set using the "arp" command.

ping 192.168.1.19
ping 192.168.1.101
arp -a

Even if you get no response to "ping" there still may be an ARP entry for the board. If you see an ARP entry then the board is communicating on Ethernet.

The Ethernet MAC (hardware) address is usually set from an EEPROM connected to an Ethernet chip. In the case of your embedded boards the Ethernet MAC address is probably compiled into the Ethernet driver. You should be able to set the MAC address using a kernel parameter for the Ethernet driver. Look at the documentation for the Ethernet driver or look at the source for the Ethernet driver to find the driver parameters.

Are you able to get one board to work by itself? Does one board respond to "ping"? Before you try to make both boards communicate, verify if you can communicate to each board individually. Also, check the MAC address for each board using "arp".