So, in my final effort, I will find the file /etc/network/interfaces, delete everything and add
# automatically generated by enigma 2
# do NOT change manually!
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet dhcp
auto wlan0
iface wlan0 inet dhcp
hwaddress ether 01:02:03:04:05:06 (other mac address)
or should I delete aeverything and put
$ ifconfig eth0 down
$ ifconfig eth0 hw ether 11:22:33:44:55:66
$ ifconfig eth0 up
hwaddress ether 11:22:33:44:55:66