检查维护系统的时候，经常会要查看服务器的网络端口是多大的，所以需要用到Linux的一个命令。

如何查看CentOS的网络带宽出口多大？可以用下面的命令来查看。

# ethtool eth0

前面是命令，后面跟的是设备名，如果对外连接的网络设备是eth1，那就需要改成：ethtool eth0

[root@localhost ~]# ethtool eth0

Settings for eth0:

Supported ports: [ TP ]

Supported link modes: 10baseT/Half 10baseT/Full

100baseT/Half 100baseT/Full

1000baseT/Full

Supported pause frame use: No

Supports auto-negotiation: Yes

Advertised link modes: 10baseT/Half 10baseT/Full

100baseT/Half 100baseT/Full

1000baseT/Full

Advertised pause frame use: No

Advertised auto-negotiation: Yes

Speed: 1000Mb/s

Duplex: Full

Port: Twisted Pair

PHYAD: 0

Transceiver: internal

Auto-negotiation: on

MDI-X: Unknown

Supports Wake-on: d

Wake-on: d

Current message level: 0x00000007 (7)

drv probe link

Link detected: yes