Sorting the connections to a linux server by its status and bu combination of source/destination IP and port

connections_by_status_and_ipport.sh

# By status
netstat -an | awk '$6 ~ /^[A-Z_]+[1-2]*$/{a[$6]++} END {for (i in a) print a[i], "\t", i}' | sort -n
# By source IP:port
netstat -an | awk '$4 ~ /^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+:[0-9]+$/{a[$4]++} END {for (i in a) print a[i], "\t", i}' | sort -n
# By destination IP:port
netstat -an | awk '$5 ~ /^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+:[0-9]+$/{a[$5]++} END {for (i in a) print a[i], "\t", i}' | sort -n
# Just by destination IP
netstat -an | awk '$5 ~ /^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+:[0-9]+$/{a[gensub(/^(.+):.+$/, "\\1", "g", $5)]++} END {for (i in a) print a[i], "\t", i}' | sort -n