查看MAC和PHY配置和状态工具有 mii-tool/ethtool. 经常使用的工具是ethtool, ethtool可以详细的描述MAC和PHY的相关信息，包括寄存器的配置，相关的统计。
使用语法
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]
命令参数说明
-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
用法举例
1. 查看ethtool的详细功能
ethtool --help
2. 查看基本信息
root@baohua-VirtualBox:/home/baohua/workspace/sourceCode# 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: off (auto) Supports Wake-on: umbg Wake-on: d Current message level: 0x00000007 (7) drv probe link Link detected: yes
3. 查看MAC和PHY的相关寄存器
root@baohua-VirtualBox:/home/baohua/workspace/sourceCode# ethtool -d eth0 MAC Registers ------------- 0x00000: CTRL (Device control register) 0x48000249 Endian mode (buffers): little Link reset: reset Set link up: 1 Invert Loss-Of-Signal: no Receive flow control: enabled Transmit flow control: disabled VLAN mode: enabled Auto speed detect: disabled Speed select: 1000Mb/s Force speed: no Force duplex: no 0x00008: STATUS (Device status register) 0x00000083 Duplex: full Link up: link config TBI mode: disabled Link speed: 1000Mb/s Bus type: PCI Bus speed: 33MHz 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: don\'t pass Receive buffer size: 2048 0x02808: RDLEN (Receive desc length) 0x00001000 0x02810: RDH (Receive desc head) 0x000000AE 0x02818: RDT (Receive desc tail) 0x000000AC 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) 0x0000008D 0x03818: TDT (Transmit desc tail) 0x0000008D 0x03820: TIDV (Transmit delay timer) 0x00000008 PHY type: M88 M88 PHY STATUS REGISTER: 0x0000BC08 Jabber: no Polarity: normal Downshifted: no MDI/MDIX: MDI Cable Length Estimate: 0-50 meters Link State: Up Speed & Duplex Resolved: Yes Page Received: Yes Duplex: Full Speed: 1000 mbps M88 PHY CONTROL REGISTER: 0x00000868 Jabber function: enabled Auto-polarity: disabled SQE Test: disabled CLK125: enabled Auto-MDIX: auto Extended 10Base-T Distance: disabled 100Base-TX Interface: MII Scrambler: enabled Force Link Good: disabled Assert CRS on Transmit: enabled
4. 查看收发包统计
root@baohua-VirtualBox:/home/baohua/workspace/sourceCode# ethtool -S eth0 NIC statistics: rx_packets: 105902 tx_packets: 14458 rx_bytes: 7561476 tx_bytes: 2602118 rx_broadcast: 105692 tx_broadcast: 3406 rx_multicast: 4 tx_multicast: 10756 rx_errors: 0 tx_errors: 0 tx_dropped: 0 multicast: 4 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: 7561476 rx_csum_offload_good: 0 rx_csum_offload_errors: 0 alloc_rx_buff_failed: 0 tx_smbus: 0 rx_smbus: 0 dropped_smbus: 0
5. 设置PHY的动作方式，速度/半双工/自动协商
ethtool -s ethX [speed 10|100|1000] [duplex half|full] [autoneg on|off]
ethtool -s eth0 autoneg off speed 100 duplex full
将 ethtool 设置永久保存在网络设备：
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
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