Archive for the tag 'netstat'

Using netstat to find largest number of established connections

To find out the largest number of established connections you can simply use something like

netstat -an | grep ‘ESTABLISHED’ | awk ‘{print $4}’ | cut -d: -f1 | uniq -c | sort -rn | head -n 1
3 192.168.1.2

To see the list of the top 10

netstat -an | grep ‘ESTABLISHED’ | awk ‘{print $4}’ | cut -d: -f1 | uniq -c | sort -rn | head -n 10
2 192.168.1.2

How to view all

netstat -an | grep ‘ESTABLISHED’ | awk ‘{print $4}’ | cut -d: -f1 | uniq -c | sort -rn
3 192.168.1.2

You can also view all but have pages so you can view each in detail

netstat -an | grep ‘ESTABLISHED’ | awk ‘{print $4}’ | cut -d: -f1 | uniq -c | sort -rn | more
8 192.168.1.2

You can show the port with:

netstat -an | grep ‘ESTABLISHED’ | awk ‘{print $4}’ | uniq -c | sort -rn
1 192.168.1.2:58632
1 192.168.1.2:58631
1 192.168.1.2:58629
1 192.168.1.2:58628
1 192.168.1.2:58627
1 192.168.1.2:58613
1 192.168.1.2:55154
1 192.168.1.2:48673
SBDavid

Using Netstat

To find out the largest number of established connections you can simply use something like

netstat -an | grep ‘ESTABLISHED’ | awk ‘{print $4}’ | cut -d: -f1 | uniq -c | sort -rn | head -n 1

To see the list of the top 10

netstat -an | grep ‘ESTABLISHED’ | awk ‘{print $4}’ | cut -d: -f1 | uniq -c | sort -rn | head -n 10

To view all

netstat -an | grep ‘ESTABLISHED’ | awk ‘{print $4}’ | cut -d: -f1 | uniq -c | sort -rn

Count the number of connections each IP makes

Use netstat command to calculate and count the number of connections each IP address makes to the server.

netstat -anp |grep ‘tcp\|udp’ | awk ‘{print $5}’ | cut -d: -f1 | sort | uniq -c | sort -n

netstat - Print network connections, routing tables, interface statistics, masquerade connections, and multicast memberships