Finding IPs connected to your web server

On Mac OS X
note: this also shows outgoing connections from web browsers

Get all IPs connected to your web server:

netstat -nat | sed -n -e '/ESTABLISHED/p' | awk '{print $5}' | sed 's/\./ /g' | awk '{print $1"."$2"."$3"."$4}' | sort

Get all unique IPs connected to your web server:

netstat -nat | sed -n -e '/ESTABLISHED/p' | awk '{print $5}' | sed 's/\./ /g' | awk '{print $1"."$2"."$3"."$4}' | sort | uniq -c | sort -n

On Linux
Get all IPs connected to your web server:

netstat -ntu | sed -e 's/::ffff://g' | awk '{print $5}' | cut -d : -f1 | sort -n

Get all unique IPs connected to your web server:

netstat -ntu | sed -e 's/::ffff://g' | awk '{print $5}' | cut -d : -f1 | sort | uniq -c | sort -n