tcp packet dump filtered by port

dump_packets.sh

# -i: The interface to listen on
# -s: Setting snaplen to 0 sets it to the default of 65535
# -B: Buffer size in KiB
# -w: File to write packets to
tcpdump -i en1 -s 0 -B 524288 -w out.pcap dst port 8080

read_packets.sh

# -s: Setting snaplen to 0 sets it to the default of 65535
# -n: Don't convert addresses to names
# -e: Print the link-level header on each dump line
# -x: In addition to printing the headers of each packet, print the data of each packet (minus its link level header) in hex.
# -vvv: Extremely verbose output
# -r: File to read
tcpdump -s 0 -n -e -x -vvv -r out.pcap