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.
--debug N
Turns on debugging messages. Argument is interpreted as a
mask:
0x01 Parser information
--json Output results in JavaScript Object Notation (JSON). Only
a subset of options support this. Those which do not will
continue to output plain text in the presence of this
option.
-I --include-statistics
Include command-related statistics in the output. This
option allows displaying relevant device statistics for
selected get commands.
-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 standard (IEEE,
IETF, etc.), or NIC- and driver-specific statistics. NIC-
and driver-specific statistics are requested when no group
of statistics is specified.
NIC- and driver-specific statistics and standard
statistics are independent, devices may implement either,
both or none. There is little commonality between naming
of NIC- and driver-specific statistics across vendors.
--all-groups
--groups [eth-phy] [eth-mac] [eth-ctrl] [rmon]
Request groups of standard device 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.
lanes N
Set number of lanes.
duplex half|full
Sets full or half duplex mode.
port tp|aui|bnc|mii
Selects device port.
master-slave preferred-master|preferred-slave|forced-
master|forced-slave
Configure MASTER/SLAVE role of the PHY. When the PHY
is configured as MASTER, the PMA Transmit function
shall source TX_TCLK from a local clock source. When
configured as SLAVE, the PMA Transmit function shall
source TX_TCLK from the clock recovered from data
stream provided by MASTER. Not all devices support
this.
preferred-master Prefer MASTER role on autonegotiation
preferred-slave Prefer SLAVE role on autonegotiation
forced-master Force the PHY in MASTER role. Can be used without autonegotiation
forced-slave Force the PHY in SLAVE role. Can be used without autonegotiation
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
0x80000000000000000 100baseT1 Full
0x40000000000000000000000 100baseFX Half
0x80000000000000000000000 100baseFX Full
0x010 1000baseT Half (not supported by IEEE standards)
0x020 1000baseT Full
0x20000 1000baseKX Full
0x20000000000 1000baseX Full
0x100000000000000000 1000baseT1 Full
0x8000 2500baseX Full (not supported by IEEE standards)
0x800000000000 2500baseT Full
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
0x8000000000000000000 100000baseKR Full
0x10000000000000000000 100000baseSR Full
0x20000000000000000000 100000baseLR_ER_FR Full
0x40000000000000000000 100000baseCR Full
0x80000000000000000000 100000baseDR Full
0x4000000000000000 200000baseKR4 Full
0x8000000000000000 200000baseSR4 Full
0x10000000000000000 200000baseLR4_ER4_FR4 Full
0x20000000000000000 200000baseDR4 Full
0x40000000000000000 200000baseCR4 Full
0x100000000000000000000 200000baseKR2 Full
0x200000000000000000000 200000baseSR2 Full
0x400000000000000000000 200000baseLR2_ER2_FR2 Full
0x800000000000000000000 200000baseDR2 Full
0x1000000000000000000000 200000baseCR2 Full
0x200000000000000000 400000baseKR8 Full
0x400000000000000000 400000baseSR8 Full
0x800000000000000000 400000baseLR8_ER8_FR8 Full
0x1000000000000000000 400000baseDR8 Full
0x2000000000000000000 400000baseCR8 Full
0x2000000000000000000000 400000baseKR4 Full
0x4000000000000000000000 400000baseSR4 Full
0x8000000000000000000000 400000baseLR4_ER4_FR4 Full
0x10000000000000000000000 400000baseDR4 Full
0x20000000000000000000000 400000baseCR4 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|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 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|sctp6
m|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
-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. When either one of page, bank or i2c parameters
is specified, dumps only of a single page or its portion
is allowed. In such a case offset and length parameters
are treated relatively to EEPROM page boundaries.
--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.
fast-link-down on|off
Specifies whether Fast Link Down should be enabled and
time until link down (if supported).
msecs N
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.
energy-detect-power-down on|off
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.
msecs N
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).
--get-tunable
Get the tunable parameters.
rx-copybreak
Get the current rx copybreak value in bytes.
tx-copybreak
Get the current tx copybreak value in bytes.
pfc-prevention-tout
Get the current pfc prevention timeout value in msecs.
--set-tunable
Set driver's tunable parameters.
rx-copybreak N
Set the rx copybreak value in bytes.
tx-copybreak N
Set the tx copybreak value in bytes.
pfc-prevention-tout N
Set pfc prevention timeout in msecs. Value of 0 means
disable and 65535 means auto.
--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|llrs [...]
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
LLRS Force LLRS-FEC 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.
q.B --cable-test
Perform a cable test and report the results. What results
are returned depends on the capabilities of the network
interface. Typically open pairs and shorted pairs can be
reported, along with pairs being O.K. When a fault is
detected the approximate distance to the fault may be
reported.
--cable-test-tdr
Perform a cable test and report the raw Time Domain
Reflectometer data. A pulse is sent down a cable pair and
the amplitude of the reflection, for a given distance, is
reported. A break in the cable returns a big reflection.
Minor damage to the cable returns a small reflection. If
the cable is shorted, the amplitude of the reflection can
be negative. By default, data is returned for lengths
between 0 and 150m at 1m steps, for all pairs. However
parameters can be passed to restrict the collection of
data. It should be noted, that the interface will round
the distances to whatever granularity is actually
implemented. This is often 0.8 of a meter. The results
should include the actual rounded first and last distance
and step size.
first N
Distance along the cable, in meters, where the first
measurement should be made.
last N
Distance along the cable, in meters, where the last
measurement should be made.
step N
Distance, in meters, between each measurement.
pair N
Which pair should be measured. Typically a cable has 4
pairs. 0 = Pair A, 1 = Pair B, ...
--monitor
Listens to netlink notification and displays them.
command
If argument matching a command is used, ethtool only
shows notifications of this type. Without such
argument or with --all, all notification types are
shown.
devname
If a device name is used as argument, only
notification for this device are shown. Default is to
show notifications for all devices.
--show-tunnels
Show tunnel-related device capabilities and state. List
UDP ports kernel has programmed the device to parse as
VxLAN, or GENEVE tunnels.
