Сервис arpwatch

gate# apt install arpwatch

gate# man arpwatch

gate# cat /etc/default/arpwatch
...
ARGS="-N -p -Q"
...
gate# systemctl enable arpwatch@eth0 --now

gate# journalctl -f
...
Mar 29 11:09:08 gate.corp13.un arpwatch[710]: changed ethernet address 192.168.13.107 08:00:27:9f:65:95 (08:00:27:d5:6c:15) eth0
Mar 29 11:09:08 gate.corp13.un arpwatch[710]: flip flop 192.168.13.107 08:00:27:d5:6c:15 (08:00:27:9f:65:95) eth0