I found it very frustrating to try to access the Xplained from SSH. It never had a MAC address set so it would assign a new one every boot and a new IP to go with it. Here are the instructions to set the MAC address so this doesn't happen any more.
First, you must have a TTL cable. These are usually about $10 US. This is a must so you can see the device boot.
Second, at the prompt to enter U-Boot hit any key to get dumped in. You should see a prompt like this: U-Boot>
Once here use the "printenv" command to view the environment variables. You should see this:
baudrate=115200
bootargs=console=ttyS0,115200 earlyprintk mtdparts=atmel_nand:256k(bootstrap)ro,512k(uboot)ro,256K(env),256k(evn_redundent),256k(spare),512k(dtb),6M(kernel)ro,-(rootfs) rootfstype=ubifs ubi.mtd=7 root=ubi0:rootfs
bootcmd=nand read 0x21000000 0x180000 0x80000;nand read 0x22000000 0x200000 0x600000;bootz 0x22000000 - 0x21000000
bootdelay=3
ethact=gmac0
stderr=serial
stdin=serial
stdout=serial
Once you have these variables you can change any here. I changed my boot delay to 5 to give me more time.
Third, using the "setenv" command you can change/set new vairables. ex : setenv ethaddr 24:56:44:22:5b:ab This sets the first MAC address. NOTE: Once this one is saved it cannot be changed without wiping the entire flash memory! At this point you can set the second MAC address using the variable eth1address. This sets the second address, and can be changed.
Fourth, use the "printenv" command again to view your changes. At this point nothing is saved to memory and can be changed/corrected including the first MAC address. EX:
baudrate=115200
bootargs=console=ttyS0,115200 earlyprintk mtdparts=atmel_nand:256k(bootstrap)ro,512k(uboot)ro,256K(env),256k(evn_redundent),256k(spare),512k(dtb),6M(kernel)ro,-(rootfs) rootfstype=ubifs ubi.mtd=7 root=ubi0:rootfs
bootcmd=nand read 0x21000000 0x180000 0x80000;nand read 0x22000000 0x200000 0x600000;bootz 0x22000000 - 0x21000000
bootdelay=5
eth1addr=22:65:46:29:4b:cb
ethact=gmac0
ethaddr=24:56:44:22:5b:ab
stderr=serial
stdin=serial
stdout=serial
Fifth, use "saveenv" to save all changes. This will write all changes to memory so they won't be lost during a reset/reboot. NOTE: Once again, after this command is used the first MAC address cannot be changed!
Finnally, you can reboot the device using the "reset" command and poof it now has MAC addresses assigned to each port. YAY!
