Linux tcpdump and ngrep

Common examples of tcpdump

Usage of expressions and | or with subnets

tcpdump -qn -i any -p -e "(dst port 9443 or dst port 22 or dst port 8672) \
  and (src net 10.34.96.128/25 or src net 10.34.97.128/25 or net 10.34.98.128/25)"
tcpdump -qn -i any -p -e "dst port 22 \
  and (src net 10.34.96.128/25 or src net 10.34.97.128/25 or net 10.34.98.128/25)"
# -q less verbose, -n no-dns, -p? -e expression

ngrep

ngrep is network packet analyzer tool, It is a grep-like tool applied to the network layer – it matches traffic passing over a network interface with tcpdump like arguments syntax. It supports IPv4/6, TCP, UDP, ICMPv4/6, IGMP as well as Raw.

sudo apt install ngrep
sudo yum install ngrep
sudo dnf install ngrep