use tunctl to add a virtual NIC

##安装tunctl软件包
##install tunctl software package

yum install tunctl.x86_64

##添加虚拟网卡设备
##add a virtual NIC device

tunctl -u alex

##设定虚拟网卡的mac地址
##configure the mac address of the NIC

/sbin/ifconfig tap0 hw ether 00:01:02:03:04:05:06 

##使用tap0虚拟网卡
##enable the virtual NIC

/sbin/ifconfig tap0 up