Below is an Unix command to list all the IP addresses connected to your server on port 80.
netstat -tn 2>/dev/null | grep :80 | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -nr | head
Output – Total connections by IP, from highest to lowest.
97 114.198.236.100
56 67.166.157.194
44 170.248.43.76
38 141.0.9.20
37 49.248.0.2
37 153.100.131.12
31 223.62.169.73
30 65.248.100.253
29 203.112.82.128
29 182.19.66.187
