Network scanning refers to a set of procedures that investigate a live host, the type of host, open ports, and the type of services running on the host. Network scanning is a part of intelligence gathering by virtue of which an attacker can create a profile of the target organization.
In this chapter, we will cover the following topics:
- How to check live systems
- Ping sweep
- TCP scanner
- How to create an efficient IP scanner
- Services running on the target machine
- The concept of a port scanner
- How to create an efficient port scanner
You should have a basic knowledge of the TCP/IP layer communication. Before proceeding further, the concept of the protocol data unit (PDU) should be clear.
PDU is a unit of data specified in the protocol. It is the generic term for data at each layer:
- For the application layer, PDU indicates data
- For the transport layer, PDU indicates...