I have compile a specific overlay for disable Ethernet "gmac1"
nano radxa-zero3-disabled-ethernet.dts
/dts-v1/;
/plugin/;
/ {
metadata {
title = "Disabled Zero 3W Ethernet";
compatible = "radxa,zero3";
category = "misc";
description = "Disabled Zero 3W Ethernet.";
};
};
&mdio1 {
status = "disabled";
};
&gmac1 {
status = "disabled";
};
and after
sudo armbian-add-overlay radxa-zero3-disabled-ethernet.dts
after reboot, all work fine
neooo@radxa-zero3:~$ sudo tcpdump
tcpdump: verbose output suppressed, use -v[v]... for full protocol decode
listening on wlan0, link-type EN10MB (Ethernet), snapshot length 262144 bytes
13:05:31.533450 IP radxa-zero3.ssh > 192.168.1.118.50080: Flags [P.], seq 776960108:776960316, ack 799701818, win 501, length 208
13:05:31.581864 IP 192.168.1.118.50080 > radxa-zero3.ssh: Flags [.], ack 208, win 1024, length 0
^C
2 packets captured
9 packets received by filter
0 packets dropped by kernel
Thanks for help
Neooostef's post in TCPDUMP error was marked as the answer