Count of Packets by Local Port

This DTrace one-liner counts UDP received packets by the local UDP port:

# dtrace -n 'udp:::receive { @[args[4]->udp_dport] = count(); }'
dtrace: description 'udp:::receive ' matched 1 probe
^C

 33294                1
 33822                1
 38961                1
 44433                1
 46258                1
 46317                1
 47511                1
 50581                1
 54685                1
 56491                1
 59056                1
 62171                1
 62769                1
 64231                1

The preceding output shows that 1 packet was received for port 33294, 1 packet was received for port 33822, and so on.