look at the icmp messages received by the host
icmpinfo is a tool for observing ICMP messages in a manner similar
to tcpdump(8).

It is implemented as a heavily modified version of BSD ping.

icmpinfo will only report weird packets by default, but it can also
dump all ICMP traffic. It is capable of running as a daemon and
reporting all traffic to the syslog.

Maintainer: The OpenBSD ports mailing-list <ports@openbsd.org>
