Centos 6.5 to limit the network card speed by Ethtool

Operating Environment:

Centos 6.5 x86_64

Ethtool

Operation Steps:

View Network Port EM1 device information at this time

[Root@ceph-osd-2 ~]# ethtool em1
Settings for EM1:
        supported ports: [TP]
        supported link modes:   10baset/ Half 10baset/full 
                                100baset/half 100baset/full 
                                1000baset/full supported 
        frame pause
        use:no 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
        Port: Twisted Pair
        phyad:1
        transceiver:internal
        auto-negotiation:on mdi-x
        : Unknown
        Supports Wake-on:g
        wake-on:d
        Link detected:yes

Use Ethtool to display the EM1 port rate, indicating that it cannot be set

[Root@ceph-osd-2 ~]# ethtool-s em1 Speed-cannot advertise speed
100

Later look up the data and set the correct method as follows

#ethtool-S Em1 speed duplex full Autoneg off

View EM1 Network information at this time

[Root@ceph-osd-2 ~]# ethtool em1
Settings for EM1:
        supported ports: [TP]
        supported link modes:   10baset/ Half 10baset/full 
                                100baset/half 100baset/full 
                                1000baset/full supported 
        frame pause
        use:no Auto-negotiation:yes
        Advertised link modes: Not  reported
        advertised pause frame use:no
        advertised Auto-negotiation:no
        speed:100mb/s
        duplex:full
        port:twisted Pair
        phyad:1
        : Internal
        auto-negotiation:off
        mdi-x: Unknown
        Supports wake-on:g
        wake-on:d
        Link detected: Yes

Configuration succeeded