When I try to use netmap under a FreeBSD 12.1 host and Zeek 3.0.1 (installed from source), returns the following error:
root@fbsdzeek01:/nsm/zeek/spool/worker-1 # /opt/zeek/bin/zeek -i netmap::vtnet2
624.635003 nm_open  NIOCREGIF failed: Invalid argument vtnet2
fatal error: problem with interface netmap::vtnet2 (Invalid argument)
bro-netmap plugin is installed. Any idea?