The solution to modify MAC address problem under Linux _linux

In Linux, modify the MAC address
# Ifdown Eth0
# ifconfig eth0 hw ether 12:34:56:78:90:12
(The modified MAC address is different from the original address)
# ifup Eth0 (modified successfully)
After, with the # Ifconfig view, MAC address changed, but then enter #service network restart or Ifdowneth0 command, the following error message appears:
Device eth0 has MAC address 12:34:56:78:90:12, instead ofconfigured address 00:0c:29:ca:b5:7d. Ignoring.

So at this time can not modify the/etc/sysconfig/network-scripts/ifcfg-eth0 file to change the IP address and other related information, because servicenetwork restart cannot make it effective, but with ifconfig Eth0 can temporarily change its IP address, reboot and return to the prototype.
Now solve
"Device eth0 has MAC address 12:34:56:78:90:12, instead ofconfigured address 00:0c:29:ca:b5:7d. Ignoring. " The problem:
This problem occurs because of the configuration file: The macaddr=00:0c:29:ca:b5:7d address in/etc/sysconfig/network-scripts/ifcfg-eth0 is different from the 12:34:56:78:90:12. You can modify the macaddr=00:0c:29:ca:b5:7d to 12:34:56:78:90:12, then the error is eliminated, you can use #servicenetwork restart, but after the restart, the MAC address back to the prototype, the solution is:
Add these three sentences to the/etc/rc.d/rc.local.
Ifconfig eth0 Down
Ifconfig eth0 Hwether 12:34:56:78:90:12
Ifconfig eth0 up
The macaddr=00:0c:29:ca:b5:7d address in/etc/sysconfig/network-scripts/ifcfg-eth0 will also be changed to 12:34:56:78:90:12
This reboot after the Mac is not afraid of recovery, and #service Networkrestart also will not appear wrong language.