# ethtool eth0
Settings for eth0:
	Supported ports: [ TP ]
	Supported link modes:   10baseT/Half 10baseT/Full
	                        100baseT/Half 100baseT/Full
	                        1000baseT/Full
	Supports auto-negotiation: Yes
	Advertised link modes:  10baseT/Half 10baseT/Full
	                        100baseT/Half 100baseT/Full
	                        1000baseT/Full
	Advertised auto-negotiation: Yes
	Speed: 1000Mb/s
	Duplex: Full
	Port: Twisted Pair
	PHYAD: 2
	Transceiver: internal
	Auto-negotiation: on
	Supports Wake-on: pumbg
	Wake-on: g
	Current message level: 0x00000001 (1)
	Link detected: yes

		

鑒別eth(x)

 簡單的方法：
一個插網綫，一個不插，運行 mii-tool 或 ethtool eth0，看狀態是否連接

另一種方法是：
tail -f /var/log/messages，當你向其中一個網口做插拔網綫的動作時，屏幕上會看到提示信息
		

最好的方法是將mac地址寫在啟動腳本內.