Check how many connections per port on the server :
netstat -tuna | awk -F’:+| +’ ‘NR>2{print $5}’ | cut -d: -f1 | sort | uniq -c | sort -n
Check how many connections per IP on the server : netstat -ntu | tail -n +3 | awk ‘{print $5}’ | cut -d: -f1 | sort | uniq -c | sort -n