Explanation:
Note, a DoS (Denial of Service) attack is different in scope from a DDoS (Distributed Denial of Service) attack. In a DoS attack, the attack on the website's network comes from just a single source (IP address) repeatedly, while in a DDos attack several Ip addresses or sources attack the network of a website.
To trace the source of various types of packets used in a DoS attack (which of less complexity than a DDos attack), a software application like Wireshark could be used to measure trace the packets used in the attack.
