At my home I use a wireless router to connect to internet, so every device uses wireless card to use it.
In this way using
sudo tcpdump -i wlan0 from my pc I should be able to see all the packets going around in the local net (thing that I couldn't do if everyone was connected using ethernet) and it looks it works.
Now I tryed
sudo tcpdump -i wlan0 host 192.168.1.3 to see only the packets of a specific pc (which is not mine but of another different pc) but I get nothing just:
****@****-pc ~ $ sudo tcpdump -i wlan0 host 192.168.1.3 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on wlan0, link-type EN10MB (Ethernet), capture size 65535 bytes
So I don't understand, why using
sudo tcpdump -i wlan0 I see everything but I can't say to just track one specific flow?