How to run script on network address change?

[Rozhuk Ivan]

Hi!


I have FreeBSD 13@amd64 router with DHCP client on uplink.

How to run script on IP address change?


I do not see events from devd, only:
!system=IFNET subsystem=em3 type=LINK_DOWN
!system=IFNET subsystem=em3 type=LINK_UP