#####   ######  #####    ###    #   #  ###  #   #  ######
##  ##  ##      ##  ##  ## ##   #   #   #   #   #  ##
#####   ####    #####   #   #   #   #   #   #   #  ####
##  #   ##      ##      ## ##    # #    #    # #   ##
##   #  ######  ##       ###      #    ###    #    ######

$ curl repovive.com/roadmaps/network-design/troubleshooting-methodology/using-netstat

░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░█████████████████████████████████████████████████████████████████████████████████████

#####   ######  #####    ###    #   #  ###  #   #  ######
##  ##  ##      ##  ##  ## ##   #   #   #   #   #  ##
#####   ####    #####   #   #   #   #   #   #   #  ####
##  #   ##      ##      ## ##    # #    #    # #   ##
##   #  ######  ##       ###      #    ###    #    ######

$ curl repovive.com/roadmaps/network-design/troubleshooting-methodology/using-netstat

Repovive

Using Netstat - Troubleshooting Methodology | Network Design | Repovive

Repovive.

Network Design26 sections · 911 units44h total

Open in Course

Using Netstat

Connection monitoring

Netstat shows active network connections and listening ports. It reveals what your system is communicating with.

Common options:

netstat -an              # All connections, numeric
netstat -ano             # Include process IDs (Windows)
netstat -tulnp           # TCP/UDP with processes (Linux)

Connection states:

LISTENING: Waiting for incoming connections
ESTABLISHED: Active connection
TIME_WAIT: Connection closed, cleaning up

What to look for:

Is the service listening on expected port?
Are connections established to correct hosts?