diff --git a/tools/testing/selftests/net/forwarding/ethtool.sh b/tools/testing/selftests/net/forwarding/ethtool.sh
new file mode 100755
index 000000000000..eb8e2a23bbb4
--- /dev/null
+++ b/tools/testing/selftests/net/forwarding/ethtool.sh
@@ -0,0 +1,318 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+ALL_TESTS="
+	same_speeds_autoneg_off
+	different_speeds_autoneg_off
+	combination_of_neg_on_and_off
+	advertise_subset_of_speeds
+	check_highest_speed_is_chosen
+	different_speeds_autoneg_on
+"
+NUM_NETIFS=2
+source lib.sh
+source ethtool_lib.sh
+
+h1_create()
+{
+	simple_if_init $h1 192.0.2.1/24
+}
+
+h1_destroy()
+{
+	simple_if_fini $h1 192.0.2.1/24
+}
+
+h2_create()
+{
+	simple_if_init $h2 192.0.2.2/24
+}
+
+h2_destroy()
+{
+	simple_if_fini $h2 192.0.2.2/24
+}
+
+setup_prepare()
+{
+	h1=${NETIFS[p1]}
+	h2=${NETIFS[p2]}
+
+	h1_create
+	h2_create
+}
+
+cleanup()
+{
+	pre_cleanup
+
+	h2_destroy
+	h1_destroy
+}
+
+different_speeds_get()
+{
+	local dev1=$1; shift
+	local dev2=$1; shift
+	local with_mode=$1; shift
+	local adver=$1; shift
+
+	local -a speeds_arr
+
+	speeds_arr=($(common_speeds_get $dev1 $dev2 $with_mode $adver))
+	if [[ ${#speeds_arr[@]} < 2 ]]; then
+		check_err 1 "cannot check different speeds. There are not enough speeds"
+	fi
+
+	echo ${speeds_arr[0]} ${speeds_arr[1]}
+}
+
+same_speeds_autoneg_off()
+{
+	# Check that when each of the reported speeds is forced, the links come
+	# up and are operational.
+	local -a speeds_arr=($(common_speeds_get $h1 $h2 0 0))
+
+	for speed in "${speeds_arr[@]}"; do
+		RET=0
+		ethtool_set $h1 speed $speed autoneg off
+		ethtool_set $h2 speed $speed autoneg off
+
+		setup_wait_dev_with_timeout $h1
+		setup_wait_dev_with_timeout $h2
+		ping_do $h1 192.0.2.2
+		check_err $? "speed $speed autoneg off"
+		log_test "force of same speed autoneg off"
+		log_info "speed = $speed"
+	done
+
+	ethtool -s $h2 autoneg on
+	ethtool -s $h1 autoneg on
+}
+
+different_speeds_autoneg_off()
+{
+	# Test that when we force different speeds, links are not up and ping
+	# fails.
+	RET=0
+
+	local -a speeds_arr=($(different_speeds_get $h1 $h2 0 0))
+	local speed1=${speeds_arr[0]}
+	local speed2=${speeds_arr[1]}
+
+	ethtool_set $h1 speed $speed1 autoneg off
+	ethtool_set $h2 speed $speed2 autoneg off
+
+	setup_wait_dev_with_timeout $h1
+	setup_wait_dev_with_timeout $h2
+	ping_do $h1 192.0.2.2
+	check_fail $? "ping with different speeds"
+
+	log_test "force of different speeds autoneg off"
+
+	ethtool -s $h2 autoneg on
+	ethtool -s $h1 autoneg on
+}
+
+combination_of_neg_on_and_off()
+{
+	# Test that when one device is forced to a speed supported by both
+	# endpoints and the other device is configured to autoneg on, the links
+	# are up and ping passes.
+	local -a speeds_arr=($(common_speeds_get $h1 $h2 0 1))
+
+	for speed in "${speeds_arr[@]}"; do
+		RET=0
+		ethtool_set $h1 speed $speed autoneg off
+
+		setup_wait_dev_with_timeout $h1
+		setup_wait_dev_with_timeout $h2
+		ping_do $h1 192.0.2.2
+		check_err $? "h1-speed=$speed autoneg off, h2 autoneg on"
+		log_test "one side with autoneg off and another with autoneg on"
+		log_info "force speed = $speed"
+	done
+
+	ethtool -s $h1 autoneg on
+}
+
+hex_speed_value_get()
+{
+	local speed=$1; shift
+
+	local shift_size=${speed_values[$speed]}
+	speed=$((0x1 << $"shift_size"))
+	printf "%#x" "$speed"
+}
+
+subset_of_common_speeds_get()
+{
+	local dev1=$1; shift
+	local dev2=$1; shift
+	local adver=$1; shift
+
+	local -a speeds_arr=($(common_speeds_get $dev1 $dev2 0 $adver))
+	local speed_to_advertise=0
+	local speed_to_remove=${speeds_arr[0]}
+	speed_to_remove+='base'
+
+	local -a speeds_mode_arr=($(common_speeds_get $dev1 $dev2 1 $adver))
+
+	for speed in ${speeds_mode_arr[@]}; do
+		if [[ $speed != $speed_to_remove* ]]; then
+			speed=$(hex_speed_value_get $speed)
+			speed_to_advertise=$(($speed_to_advertise | \
+						$speed))
+		fi
+
+	done
+
+	# Convert to hex.
+	printf "%#x" "$speed_to_advertise"
+}
+
+speed_to_advertise_get()
+{
+	# The function returns the hex number that is composed by OR-ing all
+	# the modes corresponding to the provided speed.
+	local speed_without_mode=$1; shift
+	local supported_speeds=("$@"); shift
+	local speed_to_advertise=0
+
+	speed_without_mode+='base'
+
+	for speed in ${supported_speeds[@]}; do
+		if [[ $speed == $speed_without_mode* ]]; then
+			speed=$(hex_speed_value_get $speed)
+			speed_to_advertise=$(($speed_to_advertise | \
+						$speed))
+		fi
+
+	done
+
+	# Convert to hex.
+	printf "%#x" "$speed_to_advertise"
+}
+
+advertise_subset_of_speeds()
+{
+	# Test that when one device advertises a subset of speeds and another
+	# advertises a specific speed (but all modes of this speed), the links
+	# are up and ping passes.
+	RET=0
+
+	local speed_1_to_advertise=$(subset_of_common_speeds_get $h1 $h2 1)
+	ethtool_set $h1 advertise $speed_1_to_advertise
+
+	if [ $RET != 0 ]; then
+		log_test "advertise subset of speeds"
+		return
+	fi
+
+	local -a speeds_arr_without_mode=($(common_speeds_get $h1 $h2 0 1))
+	# Check only speeds that h1 advertised. Remove the first speed.
+	unset speeds_arr_without_mode[0]
+	local -a speeds_arr_with_mode=($(common_speeds_get $h1 $h2 1 1))
+
+	for speed_value in ${speeds_arr_without_mode[@]}; do
+		RET=0
+		local speed_2_to_advertise=$(speed_to_advertise_get $speed_value \
+			"${speeds_arr_with_mode[@]}")
+		ethtool_set $h2 advertise $speed_2_to_advertise
+
+		setup_wait_dev_with_timeout $h1
+		setup_wait_dev_with_timeout $h2
+		ping_do $h1 192.0.2.2
+		check_err $? "h1=$speed_1_to_advertise, h2=$speed_2_to_advertise ($speed_value)"
+
+		log_test "advertise subset of speeds"
+		log_info "h1=$speed_1_to_advertise, h2=$speed_2_to_advertise"
+	done
+
+	ethtool -s $h2 autoneg on
+	ethtool -s $h1 autoneg on
+}
+
+check_highest_speed_is_chosen()
+{
+	# Test that when one device advertises a subset of speeds, the other
+	# chooses the highest speed. This test checks configuration without
+	# traffic.
+	RET=0
+
+	local max_speed
+	local chosen_speed
+	local speed_to_advertise=$(subset_of_common_speeds_get $h1 $h2 1)
+
+	ethtool_set $h1 advertise $speed_to_advertise
+
+	if [ $RET != 0 ]; then
+		log_test "check highest speed"
+		return
+	fi
+
+	local -a speeds_arr=($(common_speeds_get $h1 $h2 0 1))
+	# Remove the first speed, h1 does not advertise this speed.
+	unset speeds_arr[0]
+
+	max_speed=${speeds_arr[0]}
+	for current in ${speeds_arr[@]}; do
+		if [[ $current -gt $max_speed ]]; then
+			max_speed=$current
+		fi
+	done
+
+	setup_wait_dev_with_timeout $h1
+	setup_wait_dev_with_timeout $h2
+	chosen_speed=$(ethtool $h1 | grep 'Speed:')
+	chosen_speed=${chosen_speed%"Mb/s"*}
+	chosen_speed=${chosen_speed#*"Speed: "}
+	((chosen_speed == max_speed))
+	check_err $? "h1 advertise $speed_to_advertise, h2 sync to speed $chosen_speed"
+
+	log_test "check highest speed"
+
+	ethtool -s $h2 autoneg on
+	ethtool -s $h1 autoneg on
+}
+
+different_speeds_autoneg_on()
+{
+	# Test that when we configure links to advertise different speeds,
+	# links are not up and ping fails.
+	RET=0
+
+	local -a speeds=($(different_speeds_get $h1 $h2 1 1))
+	local speed1=${speeds[0]}
+	local speed2=${speeds[1]}
+
+	speed1=$(hex_speed_value_get $speed1)
+	speed2=$(hex_speed_value_get $speed2)
+
+	ethtool_set $h1 advertise $speed1
+	ethtool_set $h2 advertise $speed2
+
+	if (($RET)); then
+		setup_wait_dev_with_timeout $h1
+		setup_wait_dev_with_timeout $h2
+		ping_do $h1 192.0.2.2
+		check_fail $? "ping with different speeds autoneg on"
+	fi
+
+	log_test "advertise different speeds autoneg on"
+
+	ethtool -s $h2 autoneg on
+	ethtool -s $h1 autoneg on
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+
+declare -gA speed_values
+eval "speed_values=($(speeds_arr_get))"
+
+tests_run
+
+exit $EXIT_STATUS