basics for netstat

netstat_basics.sh

# check active connections
netstat -ant | grep 4444 | wc -l

# only established connections
netstat -ant | grep 4444 | grep -i established | wc -l
# idle connections
netstat -an -f inet | grep -v EST | grep IDLE | wc -l


# in loop
while true; do clear; netstat -an -f inet | awk '{print $2}' | cut -d. -f1-4 | sort | uniq -c | sort -n | grep -v "*.*" | tail -10; sleep 5; done

# show overall open connections on the server
while true; do clear; netstat -an -f inet | awk '{print $2}' | cut -d. -f1-4 | wc -l; sleep 5; done