[ Ethtool ] MAC update

As long as NIC driver supports the EEPROM can be updated via ethtool.
It's convenient on production line if the EEPROM is not well pre-burnt.

Ethtool write a byte:

ethtool -E $eth magic $mgc offset $off value $bye

mgc = magic composed by devID and venID, "lspci -n" to discover it
bye = byte to write
eth = ether device name, "ifconfig" to discover it
off = writing offset in EEPROM

A for loop can easily update the MAC address.

Example of updating Intel i210 MAC under CentOS

mgc=0x15338086
mac=00:11:22:33:44:55
eth=enP6p1s0
off=0
for i in {0..5}; do ethtool -E $eth magic $mgc offset $((off+i)) value 0x${mac:$((i*3)):2}; done

Checking the result by reading EEPROM.

ethtool -e $eth offset $off length 6

[ SSH ] remote unattended

sshpass -p <password> ssh -q -o "UserKnownHostsFile=/dev/null" -o "StrictHostKeyChecking=no" <user id>@<remote IP> "<command(s)>"

Cygwin works as well.