ifconfig

修改网卡的配置文件，缺省选项和参数是查看激活状态的网卡信息

$ ifconfig
eth0      Link encap:Ethernet  HWaddr b8:88:e3:e9:1f:2d  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:20102 errors:0 dropped:0 overruns:0 frame:0
          TX packets:20102 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:1897763 (1.8 MB)  TX bytes:1897763 (1.8 MB)

wlan0     Link encap:Ethernet  HWaddr e0:06:e6:cd:f8:cf  
          inet addr:192.168.1.111  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::e206:e6ff:fecd:f8cf/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:11539 errors:0 dropped:3 overruns:0 frame:0
          TX packets:7005 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:3352856 (3.3 MB)  TX bytes:891096 (891.0 KB)

说明：
eth0, wlan0 #网卡名
lo 主机环回地址
Link encap#连接类型
HWaddr #HardWareaddress，即MAC地址
inet addr #ip地址
Bcast #广播地址
Mask #子网掩码
命令格式$ifconfig [网卡名] [选项] [参数]
add [地址] #设置ip地址
del [地址] #删除ip地址
up #启动网络设备
down #关闭网络设备
hw [设备类型] [硬件地址] # 设置网络设备的类型与硬件地址
irq[IRQ地址] # 设置网络设备的IRQ
netmask [子网掩码] # 设置子网掩码
broadcast [广播地址] # 设置广播地址