Je viens d'essayer l'autre commande :
sudo tcpdump -ne ether broadcast or ether multicast |grep "192\.168\.1\."
Et voici le résultat :
tcpdump: data link type PKTAP
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on pktap, link-type PKTAP (Apple DLT_PKTAP), capture size 262144 bytes
pktap_filter_packet: pcap_add_if_info(utun5, 0) failed: not a broadcast link
4 packets captured
131 packets received by filter
0 packets dropped by kernel
17:35:38.388205 14:98:77:67:e1:04 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 272: 192.168.1.23.17500 > 255.255.255.255.17500: UDP, length 230
17:35:38.388912 14:98:77:67:e1:04 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 176: 192.168.1.23.17500 > 255.255.255.255.17500: UDP, length 134
17:35:38.389466 14:98:77:67:e1:04 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 272: 192.168.1.23.17500 > 192.168.1.255.17500: UDP, length 230
17:35:38.389829 14:98:77:67:e1:04 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 176: 192.168.1.23.17500 > 192.168.1.255.17500: UDP, length 134
Recommencé quelques instants après => 0 packets capturés.