ETHTOOL(8)

NAME
ethtool - query or control network driver and hardware settings

SYNOPSIS

ethtool devname

ethtool -h|--help

ethtool --version

ethtool -a|--show-pause devname

ethtool -A|--pause devname

ethtool -c|--show-coalesce devname

ethtool -C|--coalesce devname

ethtool -g|--show-ring devname

ethtool -G|--set-ring devname

ethtool -i|--driver devname

ethtool -d|--register-dump devname [file name]

ethtool -e|--eeprom-dump devname

ethtool -E|--change-eeprom devname

ethtool -k|--show-features|--show-offload devname

ethtool -K|--features|--offload devname feature ...

ethtool -p|--identify devname [N]

ethtool -P|--show-permaddr devname

ethtool -r|--negotiate devname

ethtool -S|--statistics devname

ethtool --phy-statistics devname

ethtool -t|--test devname [offline|online|external_lb]

ethtool -s devname [wol p|u|m|b|a|g|s|f|d...] [sopass xx:yy:zz:aa:bb:cc] [msglvl N | msglvl type ...]

ethtool -n|-u|--show-nfc|--show-ntuple devname [ rx-flow-hash tcp4|udp4|ah4|esp4|sctp4|tcp6|udp6|ah6|esp6|sctp6 |
rule N ]

ethtool -N|-U|--config-nfc|--config-ntuple devname rx-flow-hash tcp4|udp4|ah4|esp4|sctp4|tcp6|udp6|ah6|esp6|sctp6 m|v|t|s|d|f|n|r... |
flow-type ether|ip4|tcp4|udp4|sctp4|ah4|esp4|ip6|tcp6|udp6|ah6|esp6|sctp6 [src xx:yy:zz:aa:bb:cc [m xx:yy:zz:aa:bb:cc]] [dst xx:yy:zz:aa:bb:cc [m xx:yy:zz:aa:bb:cc]] [src-ip ip-address [m ip-address]] [dst-ip ip-address [m ip-address]] [dst-mac xx:yy:zz:aa:bb:cc [m xx:yy:zz:aa:bb:cc]] |
delete N

ethtool -w|--get-dump devname [data filename]

ethtool -W|--set-dump devname N

ethtool -T|--show-time-stamping devname

ethtool -x|--show-rxfh-indir|--show-rxfh devname

ethtool -X|--set-rxfh-indir|--rxfh devname [hkey xx:yy:zz:aa:bb:cc:...] [start N] [ equal N | weight W0 W1 ... | default ] [hfunc FUNC] [context CTX | new] [delete]

ethtool -f|--flash devname file [N]

ethtool -l|--show-channels devname

ethtool -L|--set-channels devname

ethtool -m|--dump-module-eeprom|--module-info devname

ethtool --show-priv-flags devname

ethtool --set-priv-flags devname flag ...

ethtool --show-eee devname

ethtool --set-eee devname

ethtool --set-phy-tunable devname [ downshift ] [ fast-link-down ] [ energy-detect-power-down ]

ethtool --get-phy-tunable devname [downshift] [fast-link-down] [energy-detect-power-down]

ethtool --reset devname [mgmt] [mgmt-shared] [irq] [irq-shared] [dma] [dma-shared] [filter] [filter-shared] [offload] [offload-shared] [mac] [mac-shared] [phy] [phy-shared] [ram] [ram-shared] [ap] [ap-shared] [dedicated] [all]

ethtool --show-fec devname

ethtool --set-fec devname encoding auto|off|rs|baser [...]

ethtool -Q|--per-queue devname [queue_mask %x] sub_command ...
 .

DESCRIPTION
ethtool is used to query and control network device driver and hardware settings, particularly for wired Ethernet devices. devname is the name of the network device on which ethtool should operate.

OPTIONS
ethtool with a single argument specifying the device name prints current settings of the specified device.

-h --help
    Shows a short help message.

--version
    Shows the ethtool version number.

-a --show-pause
    Queries the specified Ethernet device for pause parameter information.

-A --pause
    Changes the pause parameters of the specified Ethernet device.

    Specifies whether pause autonegotiation should be enabled.

    Specifies whether RX pause should be enabled.

    Specifies whether TX pause should be enabled.

-c --show-coalesce
    Queries the specified network device for coalescing information.

-C --coalesce
    Changes the coalescing settings of the specified network device.

-g --show-ring
    Queries the specified network device for rx/tx ring parameter information.

-G --set-ring
    Changes the rx/tx ring parameters of the specified network device.

    rx N
        Changes the number of ring entries for the Rx ring.

    rx-mini N
        Changes the number of ring entries for the Rx Mini ring.

    rx-jumbo N
        Changes the number of ring entries for the Rx Jumbo ring.

    tx N
        Changes the number of ring entries for the Tx ring.

-i --driver
    Queries the specified network device for associated driver information.

-d --register-dump
    Retrieves and prints a register dump for the specified network device. The register format for some devices is known and decoded others are printed in hex. When raw is enabled, then ethtool dumps the raw register data to stdout. If file is specified, then use contents of previous raw register dump, rather than reading from the device.

-e --eeprom-dump
    Retrieves and prints an EEPROM dump for the specified network device. When raw is enabled, then it dumps the raw EEPROM data to stdout. The length and offset parameters allow dumping certain portions of the EEPROM. Default is to dump the entire EEPROM.

    raw on|off

    offset N

    length N

-E --change-eeprom
    If value is specified, changes EEPROM byte for the specified network device. offset and value specify which byte and it's new value. If value is not specified, stdin is read and written to the EEPROM. The length and offset parameters allow writing to certain portions of the EEPROM. Because of the persistent nature of writing to the EEPROM, a device-specific magic key must be specified to prevent the accidental writing to the EEPROM.

-k --show-features --show-offload
    Queries the specified network device for the state of protocol offload and other features.

-K --features --offload
    Changes the offload parameters and other features of the specified network device. The following feature names are built-in and others may be defined by the kernel.

    Specifies whether RX checksumming should be enabled.

    Specifies whether TX checksumming should be enabled.

    Specifies whether scatter-gather should be enabled.

    Specifies whether TCP segmentation offload should be enabled.

    Specifies whether UDP fragmentation offload should be enabled

    Specifies whether generic segmentation offload should be enabled

    Specifies whether generic receive offload should be enabled

    Specifies whether large receive offload should be enabled

    Specifies whether RX VLAN acceleration should be enabled

    Specifies whether TX VLAN acceleration should be enabled

    Specifies whether Rx ntuple filters and actions should be enabled

    Specifies whether receive hashing offload should be enabled

-p --identify
    Initiates adapter-specific action intended to enable an operator to easily identify the adapter by sight. Typically this involves blinking one or more LEDs on the specific network port.

    Length of time to perform phys-id, in seconds.

-P --show-permaddr
    Queries the specified network device for permanent hardware address.

-r --negotiate
    Restarts auto-negotiation on the specified Ethernet device, if auto-negotiation is enabled.

-S --statistics
    Queries the specified network device for NIC- and driver-specific statistics.

--phy-statistics
    Queries the specified network device for PHY specific statistics.

-t --test
    Executes adapter selftest on the specified network device. Possible test modes are:

    offline
        Perform full set of tests, possibly interrupting normal operation during the tests,

    online
        Perform limited set of tests, not interrupting normal operation,

    external_lb
        Perform full set of tests, as for offline, and additionally an external-loopback test.

-s --change
    Allows changing some or all settings of the specified network device. All following options only apply if -s was specified.

    speed N
        Set speed in Mb/s. ethtool with just the device name as an argument will show you the supported device speeds.

    Sets full or half duplex mode.

    Selects device port.

    Selects MDI-X mode for port. May be used to override the automatic
        detection feature of most adapters. An argument of auto means automatic detection of MDI status, on forces MDI-X (crossover) mode, while off means MDI (straight through) mode. The driver should guarantee that this command takes effect immediately, and if necessary may reset the link to cause the change to take effect.

    Specifies whether autonegotiation should be enabled. Autonegotiation
        is enabled by default, but in some network devices may have trouble with it, so you can disable it if really necessary.

    advertise N
        Sets the speed and duplex advertised by autonegotiation. The argument is a hexadecimal value using one or a combination of the following values:
        0x001 | 10baseT Half
        0x002 | 10baseT Full
        0x004 | 100baseT Half
        0x008 | 100baseT Full
        0x80000000000000000 | 100baseT1 Full
        0x010 | 1000baseT Half | (not supported by IEEE standards)
        0x020 | 1000baseT Full
        0x100000000000000000 | 1000baseT1 Full
        0x20000 | 1000baseKX Full
        0x20000000000 | 1000baseX Full
        0x800000000000 | 2500baseT Full
        0x8000 | 2500baseX Full | (not supported by IEEE standards)
        0x1000000000000 | 5000baseT Full
        0x1000 | 10000baseT Full
        0x40000 | 10000baseKX4 Full
        0x80000 | 10000baseKR Full
        0x100000 | 10000baseR_FEC
        0x40000000000 | 10000baseCR Full
        0x80000000000 | 10000baseSR Full
        0x100000000000 | 10000baseLR Full
        0x200000000000 | 10000baseLRM Full
        0x400000000000 | 10000baseER Full
        0x200000 | 20000baseMLD2 Full | (not supported by IEEE standards)
        0x400000 | 20000baseKR2 Full | (not supported by IEEE standards)
        0x80000000 | 25000baseCR Full
        0x100000000 | 25000baseKR Full
        0x200000000 | 25000baseSR Full
        0x800000 | 40000baseKR4 Full
        0x1000000 | 40000baseCR4 Full
        0x2000000 | 40000baseSR4 Full
        0x4000000 | 40000baseLR4 Full
        0x400000000 | 50000baseCR2 Full
        0x800000000 | 50000baseKR2 Full
        0x10000000000 | 50000baseSR2 Full
        0x10000000000000 | 50000baseKR Full
        0x20000000000000 | 50000baseSR Full
        0x40000000000000 | 50000baseCR Full
        0x80000000000000 | 50000baseLR_ER_FR Full
        0x100000000000000 | 50000baseDR Full
        0x8000000 | 56000baseKR4 Full
        0x10000000 | 56000baseCR4 Full
        0x20000000 | 56000baseSR4 Full
        0x40000000 | 56000baseLR4 Full
        0x1000000000 | 100000baseKR4 Full
        0x2000000000 | 100000baseSR4 Full
        0x4000000000 | 100000baseCR4 Full
        0x8000000000 | 100000baseLR4_ER4 Full
        0x200000000000000 | 100000baseKR2 Full
        0x400000000000000 | 100000baseSR2 Full
        0x800000000000000 | 100000baseCR2 Full
        0x1000000000000000 | 100000baseLR2_ER2_FR2 Full
        0x2000000000000000 | 100000baseDR2 Full
        0x4000000000000000 | 200000baseKR4 Full
        0x8000000000000000 | 200000baseSR4 Full
        0x10000000000000000 | 200000baseLR4_ER4_FR4 Full
        0x20000000000000000 | 200000baseDR4 Full
        0x40000000000000000 | 200000baseCR4 Full

    phyad N
        PHY address.

    Selects transceiver type. Currently only internal and external can be
        specified, in the future further types might be added.

    wol p|u|m|b|a|g|s|f|d...
        Sets Wake-on-LAN options. Not all devices support this. The argument to this option is a string of characters specifying which options to enable.
        p | Wake on PHY activity
        u | Wake on unicast messages
        m | Wake on multicast messages
        b | Wake on broadcast messages
        a | Wake on ARP
        g | Wake on MagicPacket™
        s | Enable SecureOn™ password for MagicPacket™
        f | Wake on filter(s)
        d | Disable (wake on nothing). This option clears all previous options.

    sopass xx:yy:zz:aa:bb:cc
        Sets the SecureOn™ password. The argument to this option must be 6 bytes in Ethernet MAC hex format (xx:yy:zz:aa:bb:cc).

    msglvl N
    msglvl type ...
        Sets the driver message type flags by name or number. type names the type of message to enable or disable; N specifies the new flags numerically. The defined type names and numbers are:
        drv | 0x0001 General driver status
        probe | 0x0002 Hardware probing
        link | 0x0004 Link state
        timer | 0x0008 Periodic status check
        ifdown | 0x0010 Interface being brought down
        ifup | 0x0020 Interface being brought up
        rx_err | 0x0040 Receive error
        tx_err | 0x0080 Transmit error
        tx_queued | 0x0100 Transmit queueing
        intr | 0x0200 Interrupt handling
        tx_done | 0x0400 Transmit completion
        rx_status | 0x0800 Receive completion
        pktdata | 0x1000 Packet contents
        hw | 0x2000 Hardware status
        wol | 0x4000 Wake-on-LAN status

        The precise meanings of these type flags differ between drivers.

-n -u --show-nfc --show-ntuple
    Retrieves receive network flow classification options or rules.

    rx-flow-hash tcp4|udp4|ah4|esp4|sctp4|tcp6|udp6|ah6|esp6|sctp6
        Retrieves the hash options for the specified flow type.
        tcp4 | TCP over IPv4
        udp4 | UDP over IPv4
        ah4 | IPSEC AH over IPv4
        esp4 | IPSEC ESP over IPv4
        sctp4 | SCTP over IPv4
        tcp6 | TCP over IPv6
        udp6 | UDP over IPv6
        ah6 | IPSEC AH over IPv6
        esp6 | IPSEC ESP over IPv6
        sctp6 | SCTP over IPv6

    rule N
        Retrieves the RX classification rule with the given ID.

-N -U --config-nfc --config-ntuple
    Configures receive network flow classification options or rules.

    rx-flow-hash tcp4|udp4|ah4|esp4|sctp4|tcp6|udp6|ah6|esp6|sctp6m|v|t|s|d|f|n|r...
        Configures the hash options for the specified flow type.
        m | Hash on the Layer 2 destination address of the rx packet.
        v | Hash on the VLAN tag of the rx packet.
        t | Hash on the Layer 3 protocol field of the rx packet.
        s | Hash on the IP source address of the rx packet.
        d | Hash on the IP destination address of the rx packet.
        f | Hash on bytes 0 and 1 of the Layer 4 header of the rx packet.
        n | Hash on bytes 2 and 3 of the Layer 4 header of the rx packet.
        r | Discard all packets of this flow type. When this option is set, all other options are ignored.

    flow-type ether|ip4|tcp4|udp4|sctp4|ah4|esp4|ip6|tcp6|udp6|ah6|esp6|sctp6
        Inserts or updates a classification rule for the specified flow type.
        ether | Ethernet
        ip4 | Raw IPv4
        tcp4 | TCP over IPv4
        udp4 | UDP over IPv4
        sctp4 | SCTP over IPv4
        ah4 | IPSEC AH over IPv4
        esp4 | IPSEC ESP over IPv4
        ip6 | Raw IPv6
        tcp6 | TCP over IPv6
        udp6 | UDP over IPv6
        sctp6 | SCTP over IPv6
        ah6 | IPSEC AH over IPv6
        esp6 | IPSEC ESP over IPv6

    For all fields that allow both a value and a mask to be specified, the mask may be specified immediately after the value using the m keyword, or separately using the field name keyword with -mask appended, e.g. src-mask.

    src xx:yy:zz:aa:bb:cc [m xx:yy:zz:aa:bb:cc]
        Includes the source MAC address, specified as 6 bytes in hexadecimal separated by colons, along with an optional mask. Valid only for flow-type ether.

    dst xx:yy:zz:aa:bb:cc [m xx:yy:zz:aa:bb:cc]
        Includes the destination MAC address, specified as 6 bytes in hexadecimal separated by colons, along with an optional mask. Valid only for flow-type ether.

    proto N\fR [\fPm N\fR]\fP
        Includes the Ethernet protocol number (ethertype) and an optional mask. Valid only for flow-type ether.

    src-ip ip-address [m ip-address]
        Specify the source IP address of the incoming packet to match along with an optional mask. Valid for all IP based flow-types.

    dst-ip ip-address [m ip-address]
        Specify the destination IP address of the incoming packet to match along with an optional mask. Valid for all IP based flow-types.

    tos N\fR [\fPm N\fR]\fP
        Specify the value of the Type of Service field in the incoming packet to match along with an optional mask. Applies to all IPv4 based flow-types.

    tclass N\fR [\fPm N\fR]\fP
        Specify the value of the Traffic Class field in the incoming packet to match along with an optional mask. Applies to all IPv6 based flow-types.

    l4proto N\fR [\fPm N\fR]\fP
        Includes the layer 4 protocol number and optional mask. Valid only for flow-types ip4 and ip6.

    src-port N\fR [\fPm N\fR]\fP
        Specify the value of the source port field (applicable to TCP/UDP packets) in the incoming packet to match along with an optional mask. Valid for flow-types ip4, tcp4, udp4, and sctp4 and their IPv6 equivalents.

    dst-port N\fR [\fPm N\fR]\fP
        Specify the value of the destination port field (applicable to TCP/UDP packets)in the incoming packet to match along with an optional mask. Valid for flow-types ip4, tcp4, udp4, and sctp4 and their IPv6 equivalents.

    spi N\fR [\fPm N\fR]\fP
        Specify the value of the security parameter index field (applicable to AH/ESP packets)in the incoming packet to match along with an optional mask. Valid for flow-types ip4, ah4, and esp4 and their IPv6 equivalents.

    l4data N\fR [\fPm N\fR]\fP
        Specify the value of the first 4 Bytes of Layer 4 in the incoming packet to match along with an optional mask. Valid for ip4 and ip6 flow-types.

    vlan-etype N\fR [\fPm N\fR]\fP
        Includes the VLAN tag Ethertype and an optional mask.

    vlan N\fR [\fPm N\fR]\fP
        Includes the VLAN tag and an optional mask.

    user-def N\fR [\fPm N\fR]\fP
        Includes 64-bits of user-specific data and an optional mask.

    dst-mac xx:yy:zz:aa:bb:cc [m xx:yy:zz:aa:bb:cc]
        Includes the destination MAC address, specified as 6 bytes in hexadecimal separated by colons, along with an optional mask. Valid for all IP based flow-types.

    action N
        Specifies the Rx queue to send packets to, or some other action.
        -1 | Drop the matched flow
        -2 | Use the matched flow as a Wake-on-LAN filter
        0 or higher | Rx queue to route the flow

    context N
        Specifies the RSS context to spread packets over multiple queues; either 0 for the default RSS context, or a value returned by ethtool -X ... context new.

    vf N
        Specifies the Virtual Function the filter applies to. Not compatible with action.

    queue N
        Specifies the Rx queue to send packets to. Not compatible with action.

    loc N
        Specify the location/ID to insert the rule. This will overwrite any rule present in that location and will not go through any of the rule ordering process.

    delete N
        Deletes the RX classification rule with the given ID.

-w --get-dump
    Retrieves and prints firmware dump for the specified network device. By default, it prints out the dump flag, version and length of the dump data. When data is indicated, then ethtool fetches the dump data and directs it to a file.

-W --set-dump
    Sets the dump flag for the device.

-T --show-time-stamping
    Show the device's time stamping capabilities and associated PTP hardware clock.

-x --show-rxfh-indir --show-rxfh
    Retrieves the receive flow hash indirection table and/or RSS hash key.

-X --set-rxfh-indir --rxfh
    Configures the receive flow hash indirection table and/or RSS hash key.

    hkey
        Sets RSS hash key of the specified network device. RSS hash key should be of device supported length. Hash key format must be in xx:yy:zz:aa:bb:cc format meaning both the nibbles of a byte should be mentioned even if a nibble is zero.

    hfunc
        Sets RSS hash function of the specified network device. List of RSS hash functions which kernel supports is shown as a part of the --show-rxfh command output.

    start N
        For the equal and weight options, sets the starting receive queue for spreading flows to N.

    equal N
        Sets the receive flow hash indirection table to spread flows evenly between the first N receive queues.

    weight W0 W1 ...
        Sets the receive flow hash indirection table to spread flows between receive queues according to the given weights. The sum of the weights must be non-zero and must not exceed the size of the indirection table.

    default
        Sets the receive flow hash indirection table to its default value.

    context CTX | new
        Specifies an RSS context to act on; either new to allocate a new RSS context, or CTX, a value returned by a previous ... context new.

    delete
        Delete the specified RSS context. May only be used in conjunction with context and a non-zero CTX value.

-f --flash
    Write a firmware image to flash or other non-volatile memory on the device.

    file
        Specifies the filename of the firmware image. The firmware must first be installed in one of the directories where the kernel firmware loader or firmware agent will look, such as /lib/firmware.

    N   If the device stores multiple firmware images in separate regions of non-volatile memory, this parameter may be used to specify which region is to be written. The default is 0, requesting that all regions are written. All other values are driver-dependent.

-l --show-channels
    Queries the specified network device for the numbers of channels it has. A channel is an IRQ and the set of queues that can trigger that IRQ.

-L --set-channels
    Changes the numbers of channels of the specified network device.

    rx N
        Changes the number of channels with only receive queues.

    tx N
        Changes the number of channels with only transmit queues.

    other N
        Changes the number of channels used only for other purposes e.g. link interrupts or SR-IOV co-ordination.

    combined N
        Changes the number of multi-purpose channels.

-m --dump-module-eeprom --module-info
    Retrieves and if possible decodes the EEPROM from plugin modules, e.g SFP+, QSFP. If the driver and module support it, the optical diagnostic information is also read and decoded.

--show-priv-flags
    Queries the specified network device for its private flags. The names and meanings of private flags (if any) are defined by each network device driver.

--set-priv-flags
    Sets the device's private flags as specified.

    flag Sets the state of the named private flag.

--show-eee
    Queries the specified network device for its support of Energy-Efficient Ethernet (according to the IEEE 802.3az specifications)

--set-eee
    Sets the device EEE behaviour.

    Enables/disables the device support of EEE.

    Determines whether the device should assert its Tx LPI.

    advertise N
        Sets the speeds for which the device should advertise EEE capabilities. Values are as for --change advertise

    tx-timer N
        Sets the amount of time the device should stay in idle mode prior to asserting its Tx LPI (in microseconds). This has meaning only when Tx LPI is enabled.

--set-phy-tunable
    Sets the PHY tunable parameters.

    Specifies whether downshift should be enabled.
         | Sets the PHY downshift re-tries count.

    Specifies whether Fast Link Down should be enabled and time until link down (if supported).
         | Sets the period after which the link is reported as down. Note that the PHY may choose
         | the closest supported value. Only on reading back the tunable do you get the actual value.

    Specifies whether Energy Detect Power Down (EDPD) should be enabled (if supported).
        This will put the RX and TX circuit blocks into a low power mode, and the PHY will wake up periodically to send link pulses to avoid any lock-up situation with a peer PHY that may also have EDPD enabled. By default, this setting will also enable the periodic transmission of TX pulses.
         | Some PHYs support configuration of the wake-up interval to send TX pulses.
         | This setting allows the control of this interval, and 0 disables TX pulses
         | if the PHY supports this. Disabling TX pulses can create a lock-up situation
         | where neither of the PHYs wakes the other one. If unspecified the default
         | value (in milliseconds) will be used by the PHY.

--get-phy-tunable
    Gets the PHY tunable parameters.

    downshift
        For operation in cabling environments that are incompatible with 1000BASE-T, PHY device provides an automatic link speed downshift operation. Link speed downshift after N failed 1000BASE-T auto-negotiation attempts. Downshift is useful where cable does not have the 4 pairs instance. Gets the PHY downshift count/status.

    fast-link-down
        Depending on the mode it may take 0.5s - 1s until a broken link is reported as down. In certain use cases a link-down event needs to be reported as soon as possible. Some PHYs support a Fast Link Down Feature and may allow configuration of the delay before a broken link is reported as being down. Gets the PHY Fast Link Down status / period.

    energy-detect-power-down
        Gets the current configured setting for Energy Detect Power Down (if supported).

--reset
    Reset hardware components specified by flags and components listed below

    flags N
        Resets the components based on direct flags mask

    mgmt
        Management processor

    irq Interrupt requester

    dma DMA engine

    filter
        Filtering/flow direction

    offload
        Protocol offload

    mac Media access controller

    phy Transceiver/PHY

    ram RAM shared between multiple components ap Application Processor

    dedicated
        All components dedicated to this interface

    all All components used by this interface, even if shared

--show-fec
    Queries the specified network device for its support of Forward Error Correction.

--set-fec
    Configures Forward Error Correction for the specified network device. Forward Error Correction modes selected by a user are expected to be persisted after any hotplug events. If a module is swapped that does not support the current FEC mode, the driver or firmware must take the link down administratively and report the problem in the system logs for users to correct.

    encoding auto|off|rs|baser [...]
        Sets the FEC encoding for the device. Combinations of options are specified as e.g. encoding auto rs ; the semantics of such combinations vary between drivers.
        auto | Use the driver's default encoding
        off | Turn off FEC
        RS | Force RS-FEC encoding
        BaseR | Force BaseR encoding

-Q|--per-queue
    Applies provided sub command to specific queues.

    queue_mask %x
        Sets the specific queues which the sub command is applied to. If queue_mask is not set, the sub command will be applied to all queues.

    sub_command
        Sub command to apply. The supported sub commands include --show-coalesce and --coalesce.

BUGS
Not supported (in part or whole) on all network drivers.

AUTHOR
ethtool was written by David Miller. Modifications by Jeff Garzik, Tim Hockin, Jakub Jelinek, Andre Majorel, Eli Kupermann, Scott Feldman, Andi Kleen, Alexander Duyck, Sucheta Chakraborty, Jesse Brandeburg, Ben Hutchings, Scott Branden.

AVAILABILITY
ethtool is available from http://www.kernel.org/pub/software/network/ethtool/