DHCPCheck is an utility written to help network administrators to find rogue DHCP servers and debug DHCP problems. DHCPCheck can run in many modes, including discover (broadcast DHCPDISCOVER packets and show DHCPOFFER packets and their originators), snoop (listen to any DHCP packets running in the network), and sentry (warns the network administrator if any anomalies are found, such as nonresponding servers or unexpected responses coming from rogue servers).

This utility is currently under development.

Send discover packet and show offers:

# dhcpcheck discover -i wlp3s0