Useful commands

Check certs

openssl s_client -showcerts -servername google.com -connect google.com:443 | openssl x509 -inform pem -noout -text

tcpdump

# listen by port for eth0
sudo tcpdump -n -i eth0 -p -s 0 port 5672
# listen by protocol 
sudo tcpdump -n -i eth0 -p -s 0 proto \\icmp

vs code

command + option + arrow <-/->   :)