Display established connections broken down by a host.
Display established TCP connections broken down by a host
$ netstat -tn | awk '/ESTABLISHED/ {host=$5;sub(/:[0-9]+$/,"",host);arr[host]++} END{printf "%15s %s\n","Host","Connections";for (host in arr) { printf "%15s %s\n",host,arr[host]} }'
Host Connections 54.77.186.213 6 45.57.22.133 2 216.58.209.67 3 216.58.209.161 1 216.58.214.206 3 79.125.117.125 2 198.252.206.25 1 23.59.99.222 2 216.58.214.195 1
Display established UDP connections broken down by a host
$ netstat -un | awk '/ESTABLISHED/ {host=$5;sub(/:[0-9]+$/,"",host);arr[host]++} END{printf "%15s %s\n","Host","Connections";for (host in arr) { printf "%15s %s\n",host,arr[host]} }'
Host Connections
127.0.1.1 1
8.8.8.8 4
Display established connections broken down by a host
$ netstat -an | awk '/ESTABLISHED/ {proto=$1;host=$5;sub(/:[0-9]+$/,"",host);arr[host,proto]++} END{printf "%15s %8s %s\n","Host","Protocol","Connections";for (row in arr) {split(row,key,SUBSEP); printf "%15s %8s %11s\n",key[1],key[2],arr[key[1],key[2]] } }'
Host Protocol Connections
216.58.209.170 tcp 1
151.101.1.69 tcp 5
192.0.73.2 tcp 1
23.239.16.110 tcp 6
151.101.129.69 tcp 2
127.0.1.1 udp 1
8.8.8.8 udp 4
216.58.209.78 tcp 1
216.58.214.206 tcp 2
