Check the status of the NIC under Linux or whether it is connected

Classification:

1) through the mii-tool Directive
[Email protected] root]# Mii-tool
eth0:negotiated 100basetx-fd, link ok
Eth1:no Link
Or
[Email protected] 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
Or
[Email protected] root]#mii-tool-w
21:20:33 eth0:negotiated 100basetx-fd, link ok
21:20:33 Eth1:no Link

Mii-tool is mainly used to configure the network card operation mode of instruction, but also can be queried, monitoring and other work!

2)
[Email protected]/]#/etc/init.d/network Status
Configured devices:
Lo eth0 eth1
Currently active devices:
Lo eth0
Equivalent to
[Email protected] root]#Service--status-all
............
............
Configured devices:
Lo eth0 eth1
Currently active devices:
Lo eth0
............
............
3)ifconfig-a
[Email protected]/]#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

4)Ethtool

#ethtool eth0
Settings for eth0:
Supported ports: [MII]
Supported Link Modes:10baset/half 10baset/full
100baset/half 100baset/full
1000baset/half 1000baset/full
Supports Auto-negotiation:yes
Advertised Link Modes:10baset/half 10baset/full
100baset/half 100baset/full
1000baset/half 1000baset/full
Advertised Auto-negotiation:yes
speed:100mb/s
Duplex:full
Port:twisted Pair
Phyad:1
Transceiver:internal
Auto-negotiation:on
Supports wake-on:g
Wake-on:d
Current message level:0x000000ff (255)
Link Detected:yes

#ethtool eth1

Settings for eth1:
Supported ports: [MII]
Supported Link Modes:10baset/half 10baset/full
100baset/half 100baset/full
1000baset/half 1000baset/full
Supports Auto-negotiation:yes
Advertised Link Modes:10baset/half 10baset/full
100baset/half 100baset/full
1000baset/half 1000baset/full
Advertised Auto-negotiation:yes
speed:unknown! (0)
Duplex:half
Port:twisted Pair
Phyad:1
Transceiver:internal
Auto-negotiation:on
Supports wake-on:g
Wake-on:d
Current message level:0x000000ff (255)
Link Detected:no
From the above can be seen eth0 is connected, eth1 no connection

Check the status of the NIC under Linux or whether it is connected