Install arpalert by entering the following commands in the terminal:
sudo apt update sudo apt install arpalert
monitor ARP changes in ethernet networks
The arpalert daemon is a security tool that listens on a network interface (without using 'promiscuous' mode) and catches all conversations of MAC address to IP request to alert of possibility of ARP spoofing attack. . It compares the mac addresses it detected with a pre-configured list of authorized MAC addresses. If the MAC is not in list, arpalert launches a pre-defined user script with the MAC address and IP address as parameters. . If you need to use a list of authorized MAC addresses, this package should suit your needs, otherwise arpwatch may be also fine.