如何不被忽悠？linux/centos如何查看网卡是100M还是1000M？检查100兆还是千兆（1GBPS）带宽接入，请看下面命令

[[email protected]]# mii-tool -V
mii-tool.c 1.9 2000/04/28 00:56:08 (David Hinds)
SIOCGMIIREG on eth0 failed: Input/output error
eth0: negotiated 100baseTx-FD, link ok

[[email protected]]# mii-tool -v
SIOCGMIIREG on eth0 failed: Input/output error
eth0: negotiated 100baseTx-FD, link ok
  product info: vendor 00:aa:00, model 57 rev 0
  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

[[email protected]]# 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: 100Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 1
        Transceiver: internal
        Auto-negotiation: on
        Supports Wake-on: pumbag
        Wake-on: g
        Current message level: 0x00000001 (1)
        Link detected: yes

要测试是否是1000M端口，最保险的说用wget测试一个对方的带宽足够大的下载地址：

wget http://cachefly.cachefly.net/100mb.test
--2011-03-14 22:19:12--  http://cachefly.cachefly.net/100mb.test
Resolving cachefly.cachefly.net... 205.234.175.175
Connecting to cachefly.cachefly.net|205.234.175.175|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 104857600 (100M) [application/octet-stream]
Saving to: `100mb.test.2'

100%[===================================================================================================================>] 104,857,600 39.1M/s   in 2.6s   

2011-03-14 22:19:14 (39.1 MB/s) - `100mb.test.2' saved [104857600/104857600]

如果下载速度能超过15MB/s，那么不是100M端口了，通常就是1000M端口
 
 

如果是独立服务器，可以通过下面命令核查网卡端口：

[[email protected] ]# 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: 1
        Transceiver: internal
        Auto-negotiation: on
        Supports Wake-on: pumbag
        Wake-on: g
        Current message level: 0x00000001 (1)
        Link detected: yes