NetworkManager

# emerge net-misc/networkmanager
# rc-update del net.eth0
# nano /etc/udev/rules.d/70-persistent-net.rules

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="your eth0 mac address", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="your wlan0 mac address", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="wlan*", NAME="wlan0"


# nano /etc/conf.d/net

routes_eth0="default via 192.168.0.1"
auto_eth0="true"
config_eth0="192.168.0.10/24"
enable_ipv6_eth0="false"


# /etc/init.d/NetworkManager start