A denial-of-service attack (DoS attack) or distributed denial-of-service attack (DDoS attack) is an attempt to make a computer resource unavailable to its intended users.
As like in linux server we can use the netstat commnet here too. Here I am explaining the netstat command use and example on windows server.
Step1: Login to RDP server via rdp client.
Step2: Open command prompt by visiting Start > Run > Type “cmd” in box.
Step3: netstat is a command line utility which displays protocol statistics and current TCP/IP network connections in a system. Type the following command to see all connections:
n: Displays active TCP connections.
o: Displays active TCP connections and includes the process ID (PID) for each connection. You can find the application based on the PID on the Processes tab in Windows Task Manager.
a: Displays all active TCP connections and the TCP and UDP ports on which the computer is listening.
Step4: You can use find command as filter to searches for a specific string of text in a file. In the following example you are filtering out port 80 traffic:
netstat -ano | find /c "80"
The above example has four foreign connection to its pot 80.
Find the IP address which is having maximum number of connection and block it using Cisco firewall or IPSec.