Tcpdump
Display Available Interfaces
tcpdump -D
Capture Packets from Specific Interface
tcpdump -i eth0
Print Captured Packets in ASCII
tcpdump -A -i eth0
Display Captured Packets in HEX and ASCII
tcpdump -XX -i eth0
Capture only TCP Packets.
tcpdump -i eth0 tcp
Capture only UPD Packets.
tcpdump -i eth0 udp
Capture Packet from Specific Port
tcpdump -i eth0 port <port>
Capture Packets from source IP
tcpdump -i eth0 src <ip>
Capture Packets from destination IP
tcpdump -i eth0 dst <ip>