查看Linux下网卡连接状态（up还是down)

文章来至http://hi.baidu.com/nan5715077/blog/item/4bd02f071b5f01ca7a8947cd.html

 第1种方法

    [root@localhost /]# ifconfig -a
    eth0   Link encap:Ethernet HWaddr 00:09:6B:09:08:FC 
          inet addr:192.168.10.1 Bcast:192.168.10.255 Mask:255.255.255.0
          inet6 addr: fe80::209:6bff:fe09:8fc/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:106732953 errors:0 dropped:0 overruns:0 frame:0
          TX packets:104379788 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          RX bytes:2351331877 (2.1 GiB) TX bytes:391707945 (373.5 MiB)
          Base address:0x2500 Memory:fbfe0000-fc000000 
   eth1    Link encap:Ethernet HWaddr 00:09:6B:09:08:FD 
          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)
          Base address:0x2540 Memory:fbfc0000-fbfe0000

 

 

[root@localhost /root]# ifconfig
eth0      Link encap:Ethernet HWaddr 00:19:DB:41:08:1B 
          inet addr:211.100.10.235 Bcast:211.100.10.235 Mask:255.255.255.255
          UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1
          RX packets:178812 errors:0 dropped:0 overruns:0 frame:0
          TX packets:153415 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          RX bytes:33094019 (31.5 MiB) TX bytes:71911163 (68.5 MiB)
          Base address:0x8f00 Memory:fd6e0000-fd700000

eth1      Link encap:Ethernet HWaddr 00:19:DB:41:08:1C 
          inet addr:192.168.1.115 Bcast:192.168.1.255 Mask:255.255.255.0
          UP BROADCAST MULTICAST MTU:1500 Metric:1
          RX packets:13805 errors:0 dropped:0 overruns:0 frame:0
          TX packets:11356 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:1520439 (1.4 MiB) TX bytes:5406527 (5.1 MiB)
          Base address:0x7f00 Memory:fd2e0000-fd300000

eth2      Link encap:Ethernet HWaddr 00:19:DB:41:08:1D 
          inet addr:202.194.99.62 Bcast:202.194.99.62 Mask:255.255.255.255
          UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1
          RX packets:158024 errors:0 dropped:0 overruns:0 frame:0
          TX packets:182280 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:74748049 (71.2 MiB) TX bytes:33535454 (31.9 MiB)
          Base address:0xdf00 Memory:fdee0000-fdf00000

lo        Link encap:Local Loopback 
          inet addr:127.0.0.1 Mask:255.0.0.0
          UP LOOPBACK RUNNING MTU:16436 Metric:1
          RX packets:99 errors:0 dropped:0 overruns:0 frame:0
          TX packets:99 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:12978 (12.6 kiB) TX bytes:12978 (12.6 kiB)

第二种方法，通过mii-tool指令

       [root@localhost root]#  mii-tool
         eth0: negotiated 100baseTx-FD,  link ok
        eth1:  no link

       或

       [root@localhost root]#  mii-tool -v
        eth0: negotiated 100baseTx-FD,  link ok
         product info: vendor 00:50:43, model 2 rev 3
          basic mode:   autonegotiation enabled
          basic status: autonegotiation complete, link ok
         capabilities: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD
          advertising: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD flow-control
         link partner: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD
        eth1:  no link
          product info: vendor 00:50:43, model 2 rev 3
          basic mode:   autonegotiation enabled
           basic status: no link
          capabilities: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD
          advertising: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD flow-control

       或

      [root@localhost root]# mii-tool -w
       21:20:33 eth0: negotiated 100baseTx-FD, link ok
        21:20:33 eth1: no link

ubuntu系统中重启网络服务：
/etc/init.d/networking restart

禁用网卡eth0:
ifconfig eth0 down

激活网卡eth0:
ifconfig eth0 up

网卡eth1同上。