ethtool 是用于查询及设置网卡参数的命令。
2.1 命令格式
(1) 语法
ethtool [ -a | -c | -g | -i | -d | -k | -r | -S |] ethX
ethtool [-A] ethX [autoneg on|off] [rx on|off] [tx on|off]
ethtool [-C] ethX [adaptive-rx on|off] [adaptive-tx on|off] [rx-usecs N]
[rx-frames N] [rx-usecs-irq N] [rx-frames-irq N] [tx-usecs N]
[tx-frames N] [tx-usecs-irq N] [tx-frames-irq N] [stats-block-usecs N]
[pkt-rate-low N][rx-usecs-low N] [rx-frames-low N] [tx-usecs-low N]
[tx-frames-low N] [pkt-rate-high N] [rx-usecs-high N] [rx-frames-high N]
[tx-usecs-high N] [tx-frames-high N] [sample-interval N]
ethtool [-G] ethX [rx N] [rx-mini N] [rx-jumbo N] [tx N]
ethtool [-e] ethX [raw on|off] [offset N] [length N]
ethtool [-E] ethX [magic N] [offset N] [value N]
ethtool [-K] ethX [rx on|off] [tx on|off] [sg on|off] [tso on|off]
ethtool [-p] ethX [N]
ethtool [-t] ethX [offline|online]
ethtool [-s] ethX [speed 10|100|1000] [duplex half|full] [autoneg on|off]
[port tp|aui|bnc|mii] [phyad N] [xcvr internal|external]
[wol p|u|m|b|a|g|s|d…] [sopass xx:yy:zz:aa:bb:cc] [msglvl N]
(2) 描述
ethX是以太网卡的名称，Linux系统将检测到的第一块以太网卡命名为eth0, 第二块为eth1,…….。
2.2 命令常见参数说明
参数
说明
-a
查看网卡中接收模块RX、发送模块TX和Autonegotiate模块的状态：启动on 或 停用off。
-A
修改网卡中 接收模块RX、发送模块TX和Autonegotiate模块的状态：启动on 或 停用off。
-c
display the Coalesce(聚合、联合) information of the specified ethernet card.聚合网口信息，使看起来更有规律。
-C
Change the Coalesce setting of the specified ethernet card.修改网卡聚合信息。
-g
Display the rx/tx ring parameter information of the specified ethernet card. 显示网卡的接收/发送环形参数。
-G
Change the rx/tx ring setting of the specified ethernet card. 修改网卡的接收/发送环形参数。
-i
显示网卡驱动的信息，如驱动的名称、版本等。
-d
显示register dump信息, 部分网卡驱动不支持该选项。
-e
显示EEPROM dump信息，部分网卡驱动不支持该选项。
-E
修改网卡EEPROM byte.
-k
显示网卡Offload参数的状态：on 或 off，包括rx-checksumming、tx-checksumming等。
-K
修改网卡Offload参数的状态
-p
用于区别不同ethX对应网卡的物理位置，常用的方法是使网卡port上的led不断的闪；N指示了网卡闪的持续时间，以秒为单位。
-r
如果auto-negotiation模块的状态为on，则restarts auto-negotiation.
-s
修改网卡的部分配置，包括网卡速度、单工/全双工模式、mac地址等。加上-s选项修改的内容才会生效
-S
显示NIC- and driver-specific 的统计参数，如网卡接收/发送的字节数、接收/发送的广播包个数等。
-t
让网卡执行自我检测，有两种模式：offline or online.
2.3 输出详解
[root@localhost ~]# ethtool eth0
Settings for eth0:
Supported ports: [ TP ]
// 支持模式
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supported pause frame use: No
Supports auto-negotiation: Yes // 支持自动协商
Supported FEC modes: Not reported
// 通告模式
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: Yes // 使用自动协商
Advertised FEC modes: Not reported
Speed: 1000Mb/s // 当前速率 1000Mb/s
Duplex: Full // 工作模式为全双工
Port: Twisted Pair
PHYAD: 0
Transceiver: internal
Auto-negotiation: on // 自动协商打开
MDI-X: off (auto)
Supports Wake-on: d
Wake-on: d
Current message level: 0x00000007 (7)
drv probe link
Link detected: yes
3.1 查询网口基本设置
(1)命令
ethtool ethx
(2) 功能
查询ethx网口基本设置，其中 x 是对应网卡的编号，如eth0、eth1等等。
(3) 实例
[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
Supported FEC modes: Not reported
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Speed: 1000Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 0
Transceiver: internal
Auto-negotiation: on
MDI-X: off (auto)
Supports Wake-on: d
Wake-on: d
Current message level: 0x00000007 (7)
drv probe link
Link detected: yes
3.2 查询网口的驱动相关信息
(1) 命令
ethtool -i ethx
(2) 功能
查询网口的驱动相关信息，如驱动名称、版本信息等。
(3) 实例
[root@localhost ~]# ethtool -i eth0
driver: e1000
version: 7.3.21-k8-NAPI
firmware-version:
expansion-rom-version:
bus-info: 0000:02:01.0
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: no
3.3 查询ethx网口注册性信息
(1) 命令
ethtool -d ethx
(2) 功能
查询网口注册性信息。
(3) 实例
0x00000: CTRL (Device control register) 0x00C00249
Endian mode (buffers): little
Link reset: reset
Set link up: 1
Invert Loss-Of-Signal: no
Receive flow control: disabled
Transmit flow control: disabled
VLAN mode: disabled
Auto speed detect: disabled
Speed select: 1000Mb/s
Force speed: no
Force duplex: no
0x00008: STATUS (Device status register) 0x0000CB83
Duplex: full
Link up: link config
TBI mode: disabled
Link speed: 1000Mb/s
Bus type: PCI
Bus speed: 66MHz
Bus width: 32-bit
0x00100: RCTL (Receive control register) 0x00008002
Receiver: enabled
Store bad packets: disabled
Unicast promiscuous: disabled
Multicast promiscuous: disabled
Long packet: disabled
Descriptor minimum threshold size: 1/2
Broadcast accept mode: accept
VLAN filter: disabled
Canonical form indicator: disabled
Discard pause frames: filtered
Pass MAC control frames: do not pass
Receive buffer size: 2048
0x02808: RDLEN (Receive desc length) 0x00001000
0x02810: RDH (Receive desc head) 0x00000035
0x02818: RDT (Receive desc tail) 0x00000033
0x02820: RDTR (Receive delay timer) 0x00000000
0x00400: TCTL (Transmit ctrl register) 0x0103F0FA
Transmitter: enabled
Pad short packets: enabled
Software XOFF Transmission: disabled
Re-transmit on late collision: enabled
0x03808: TDLEN (Transmit desc length) 0x00001000
0x03810: TDH (Transmit desc head) 0x00000000
0x03818: TDT (Transmit desc tail) 0x00000000
0x03820: TIDV (Transmit delay timer) 0x00000008
PHY type: M88
M88 PHY STATUS REGISTER: 0x0000AC00
Jabber: no
Polarity: normal
Downshifted: no
MDI/MDIX: MDI
Cable Length Estimate: 0-50 meters
Link State: Up
Speed & Duplex Resolved: Yes
Page Received: No
Duplex: Full
Speed: 1000 mbps
M88 PHY CONTROL REGISTER: 0x00000B68
Jabber function: enabled
Auto-polarity: disabled
SQE Test: disabled
CLK125: enabled
Auto-MDIX: auto
Extended 10Base-T Distance: disabled
100Base-TX Interface: 5-bit
Scrambler: disabled
Force Link Good: disabled
Assert CRS on Transmit: enabled
3.4 查询网口收发包统计
(1) 命令
ethtool -S ethx
(2) 功能
查询网口收发包统计。
(3) 实例
[root@localhost ~]# ethtool -S eth0
NIC statistics:
rx_packets: 447
tx_packets: 17
rx_bytes: 37053
tx_bytes: 1268
rx_broadcast: 0
tx_broadcast: 0
rx_multicast: 0
tx_multicast: 0
rx_errors: 0
tx_errors: 0
tx_dropped: 0
multicast: 0
collisions: 0
rx_length_errors: 0
rx_over_errors: 0
rx_crc_errors: 0
rx_frame_errors: 0
rx_no_buffer_count: 0
rx_missed_errors: 0
tx_aborted_errors: 0
tx_carrier_errors: 0
tx_fifo_errors: 0
tx_heartbeat_errors: 0
tx_window_errors: 0
tx_abort_late_coll: 0
tx_deferred_ok: 0
tx_single_coll_ok: 0
tx_multi_coll_ok: 0
tx_timeout_count: 0
tx_restart_queue: 0
rx_long_length_errors: 0
rx_short_length_errors: 0
rx_align_errors: 0
tx_tcp_seg_good: 0
tx_tcp_seg_failed: 0
rx_flow_control_xon: 0
rx_flow_control_xoff: 0
tx_flow_control_xon: 0
tx_flow_control_xoff: 0
rx_long_byte_count: 37053
rx_csum_offload_good: 67
rx_csum_offload_errors: 0
alloc_rx_buff_failed: 0
tx_smbus: 0
rx_smbus: 0
dropped_smbus: 0
3.5 设置网口工作方式
(1) 命令
ethtool -s ethX [speed 10|100|1000] [duplex half|full] [autoneg on|off]
(2) 功能
设置网口速率10/100/1000M、设置网口半/全双工、设置网口是否自协商。自动协商关闭后，重新打开即可恢复原来的选项。
(3) 实例
[root@localhost ~]# ethtool -s eth0 autoneg off speed 100 duplex full
[root@localhost ~]#
[root@localhost ~]#
[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
Supported FEC modes: Not reported
Advertised link modes: Not reported
Advertised pause frame use: No
Advertised auto-negotiation: No
Advertised FEC modes: Not reported
Speed: 100Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 0
Transceiver: internal
Auto-negotiation: off
MDI-X: off (auto)
Supports Wake-on: d
Wake-on: d
Current message level: 0x00000007 (7)
drv probe link
Link detected: yes
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# ethtool -s eth0 autoneg on
[root@localhost ~]#
[root@localhost ~]#
[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
Supported FEC modes: Not reported
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Speed: 1000Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 0
Transceiver: internal
Auto-negotiation: on
MDI-X: off (auto)
Supports Wake-on: d
Wake-on: d
Current message level: 0x00000007 (7)
drv probe link
Link detected: yes
3.6 指定通过自动协商机制通告的速度和双工方式
(1) 命令
ethtool -s ethX advertise N
(2) 功能
指定通过自动协商机制通告的速度和双工方式。N为十六进制值，如0x008表示100Mb/s+全双工、0x020表示1000Mb/s+全双工。
(3) 实例
[root@localhost ~]# ethtool -s eth0 advertise 0x008
[root@localhost ~]#
[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
Supported FEC modes: Not reported
Advertised link modes: 100baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Speed: 1000Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 0
Transceiver: internal
Auto-negotiation: on
MDI-X: off (auto)
Supports Wake-on: d
Wake-on: d
Current message level: 0x00000007 (7)
drv probe link
Link detected: yes
3.7 其它
(1) 停止网卡的发送模块TX，请输入：
ethtool -A tx off eth0
操作完毕后，可输入：ethtool -a eth0，查看tx模块是否已被停止。
(2) 关闭网卡对收到的数据包的校验功能，请输入：
ethtool -K eth0 rx off
操作完毕后，可输入：ethtool -k eth0，查看校验功能是否已被停止。
(3) 如果机器上安装了两块网卡，那么eth0对应着哪块网卡呢？输入：
ethtool -p eth0 10
操作完毕后，看哪块网卡的led灯在闪，eth0就对应着哪块网卡。
(4) 查看网卡，在接收/发送数据时，有没有出错？请输入：
ethtool -S eth0
(5) 将千兆网卡的速度降为百兆，请输入：
ethtool -s eth0 speed 100
4 永久保存配置
将 ethtool 设置永久保存在网络设备有两种方法，一种是写入网口配置文件中，一种是开机自启动脚本。
(1) ethtool 设置可通过 /etc/sysconfig/network-scripts/ifcfg-ethx 文件保存，从而在设备下次启动时激活选项。
例如：
ethtool -s eth0 speed 100 duplex full autoneg off
此指令将eth1设备设置为全双工自适应，速度为100Mbs。若要eth0启动时设置这些参数, 修改文件/etc/sysconfig/network-scripts/ifcfg-eth1 ，添加如下一行:
ETHTOOL_OPTS=“speed 100 duplex full autoneg off”
(2) 将ethtool设置写入/etc/rc.d/rc.local之中，开机自动执行命令设置。
ethtool -s eth0 speed 100 duplex full autoneg off