# Strace
` strace -e trace=open,read ls /`

# File descriptos

- which files and libs process PID uses
`lsof -p PID`

- which ports and protocols are listening
`lsof -s -p PID`

# UDP publish
echo "Never gonna give you up" > nc -4u host 1212

# Network watches

tcpdump -A -s0 -ilo tcp port 6379

tcpdump [-Asi] COMMAND

-A      for ASCII
-s      for size of packets. If 0, no size
-i      for the network interface

COMANND listen a port, a socker