Provided by: ethtool_4.15-0ubuntu1_amd64 bug

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 [autoneg on|off] [rx on|off] [tx on|off]

       ethtool -c|--show-coalesce devname

       ethtool -C|--coalesce devname [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|--show-ring devname

       ethtool -G|--set-ring devname [rx N] [rx-mini N] [rx-jumbo N] [tx N]

       ethtool -i|--driver devname

       ethtool -d|--register-dump devname [raw on|off] [hex on|off] [file name]

       ethtool -e|--eeprom-dump devname [raw on|off] [offset N] [length N]

       ethtool -E|--change-eeprom devname [magic N] [offset N] [length N] [value N]

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

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

       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 [speed N] [duplex half|full] [port tp|aui|bnc|mii] [mdix auto|on|off]
              [autoneg on|off] [advertise N] [phyad N] [xcvr internal|external]
              [wol p|u|m|b|a|g|s|d...]  [sopass xx:yy:zz:aa:bb:cc] [msglvl N | msglvl type on|off
              ...]

       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]] [proto N [m N]] [src-ip ip-
              address [m ip-address]] [dst-ip ip-address [m ip-address]] [tos N [m N]]
              [tclass N [m N]] [l4proto N [m N]] [src-port N [m N]] [dst-port N [m N]]
              [spi N [m N]] [l4data N [m N]] [vlan-etype N [m N]] [vlan N [m N]]
              [user-def N [m N]] [dst-mac xx:yy:zz:aa:bb:cc [m xx:yy:zz:aa:bb:cc]] [action N]
              [loc N] |
              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:...]  [ equal N |
              weight W0 W1 ... | default ] [hfunc FUNC]

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

       ethtool -l|--show-channels devname

       ethtool -L|--set-channels devname [rx N] [tx N] [other N] [combined N]

       ethtool -m|--dump-module-eeprom|--module-info devname [raw on|off] [hex on|off] [offset N]
              [length N]

       ethtool --show-priv-flags devname

       ethtool --set-priv-flags devname flag on|off ...

       ethtool --show-eee devname

       ethtool --set-eee devname [eee on|off] [tx-lpi on|off] [tx-timer N] [advertise N]

       ethtool --set-phy-tunable devname [ downshift on|off [count N] ]

       ethtool --get-phy-tunable devname [downshift]

       ethtool --reset devname [flags N] [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]

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.

           autoneg on|off
                  Specifies whether pause autonegotiation should be enabled.

           rx on|off
                  Specifies whether RX pause should be enabled.

           tx on|off
                  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.

           rx on|off
                  Specifies whether RX checksumming should be enabled.

           tx on|off
                  Specifies whether TX checksumming should be enabled.

           sg on|off
                  Specifies whether scatter-gather should be enabled.

           tso on|off
                  Specifies whether TCP segmentation offload should be enabled.

           ufo on|off
                  Specifies whether UDP fragmentation offload should be enabled

           gso on|off
                  Specifies whether generic segmentation offload should be enabled

           gro on|off
                  Specifies whether generic receive offload should be enabled

           lro on|off
                  Specifies whether large receive offload should be enabled

           rxvlan on|off
                  Specifies whether RX VLAN acceleration should be enabled

           txvlan on|off
                  Specifies whether TX VLAN acceleration should be enabled

           ntuple on|off
                  Specifies whether Rx ntuple filters and actions should be enabled

           rxhash on|off
                  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.

           [ N]   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.

           duplex half|full
                  Sets full or half duplex mode.

           port tp|aui|bnc|mii
                  Selects device port.

           mdix auto|on|off
                  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.

           autoneg on|off
                  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
                  0x010             1000baseT Half           (not supported by IEEE standards)
                  0x020             1000baseT 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
                  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
                  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

           phyad N
                  PHY address.

           xcvr internal|external
                  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|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™
                  d   Disable  (wake  on  nothing).  This option
                      clears all previous options.

           sopass xx:yy:zz:aa:bb:ccSets 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 on|off ...
                  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 [m N]
                  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 [m N]
                  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 [m N]
                  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 [m N]
                  Includes the layer 4 protocol number and optional mask.  Valid only  for  flow-
                  types ip4 and ip6.

           src-port N [m N]
                  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 [m N]
                  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 [m N]
                  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 [m N]
                  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 [m N]
                  Includes the VLAN tag Ethertype and an optional mask.

           vlan N [m N]
                  Includes the VLAN tag and an optional mask.

           user-def N [m N]
                  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
                  0 or higher   Rx queue to route the flow

           vf N   Specifies the Virtual Function the filter applies to. A value  of  0  indicates
                  the PF, and thus the VF index is offset by 1. 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.

           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.

       -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 on|off 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.

           eee on|off
                  Enables/disables the device support of EEE.

           tx-lpi on|off
                  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.

           downshift on|off
                  Specifies whether downshift should be enabled

                  count N
                  Sets the PHY downshift re-tries count.

       --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.

       --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.

                  auto    Use the driver's default encoding
                  off     Turn off FEC
                  RS      Force RS-FEC encoding
                  BaseR   Force BaseR encoding

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/