Tcpdump
tcpdump
tcpdump -i <network_interface> -s 0 -w <file>
Capture packets to host [1]
tcpdump -i any -s 0 -w <file> host 10.1.1.1
tcpdump -i <network_interface> -s 0 -w <file> host 10.1.1.1
Capture packets and specify both IP and port [2]
tcpdump -i enp1s9 dst 192.168.6.1 and src 192.168.6.2 and src port 80
ipv6
tcpdump -t -n -i eth0 -s 512 -vv ip6 or proto ipv6