What Is Network Scanning and Why It Matters

By Alex Carter on October 4, 2024

A network security scanner helps simplify monitoring, maintenance, and security assessment. By identifying active devices and monitoring the interactions between network components, it gives useful data. Maintaining system security requires an understanding of how a network scanner operates. Network scanning is still a useful technique for protecting networks against various cyber threats as cybersecurity advances.

Types of Network Scanning

Network scans are often classified into two types: active and passive scanning. They can also be separated according to their unique purpose.

Host Scanning

Host scanning focuses on detecting active host systems within a network. This is often done by sending ping requests to each IP address. Active hosts respond while non-responding systems may be flagged as potential vulnerabilities. Cyber attackers use this method to locate systems that could be targeted.

Port Scanning

Port scanning detects open, vulnerable, or malfunctioning ports on a system. The scanner sends packets to various ports and monitors the answers while attempting to connect to the services that utilize those ports. Cybercriminals constantly check ports for potential access points.

Network Scanning

Network scanning examines IP addresses to identify linked devices, operating systems, and services. It may also generate a visual network map to aid in comprehending the overall network structure.

External Vulnerability Scans

These scans search for weaknesses in the network from an outsider’s perspective. Common targets include misconfigured or outdated firewalls, open ports, unpatched devices, and unsecured IoT endpoints. Vulnerability scanners assess the network much like a potential attacker would.

Total Assessment Scan

This thorough scan examines every device associated with an IP address. It checks for security status, patch updates, recent usage, antivirus protection, and the presence of endpoint detection and response (EDR) systems.

Penetration Testing

Penetration testing, often known as ethical hacking, is the simulation of real-world cyber assaults. It includes circumventing security measures, detecting vulnerabilities, investigating vulnerable systems, and assessing network threats. Before carrying out any pen tests, the company or clients concerned should always provide their approval.

How Network Scanning Works

The methods used for network scanning vary depending on the network type and protocol. In Internet Protocol (IP) networks, scanning often begins by sending basic messages, such as ping queries, to each IP address within a specified range. If a device replies, the scanner uses different protocols to acquire further information about it. This process is referred to as active scanning.

With passive scanning, however, network traffic must be continuously monitored for unusual or suspicious activities, such as malicious code. Potential threats are marked for further analysis without having to deal directly with network equipment.

Network scanning plays a crucial role in network monitoring and management. Administrators commonly perform scans to:

• Discover devices and users connected to the network and build an inventory;
• Assess the current status of systems, devices, and their performance;
• Compare actual network elements against an expected list to evaluate network health.

Cybercriminals often rely on the same scanning methods used by administrators. A typical attack scenario begins with identifying a target’s IP address range through the domain name system (DNS) or WHOIS protocol. Attackers then scan the range to detect servers, operating systems, system architecture, and services in use.

Why Is Network Scanning Essential for Security and Network Health?

Regular network scanning is essential for maintaining system health and reducing the risk of attack due to the increase in cyber threats and network vulnerabilities. It helps detect potential risks early and keeps systems protected. For additional strategies to strengthen protection, explore how cyber security for small business plays a vital role in reducing risks and improving overall defense.

Although scanning may slightly affect performance, it provides valuable insights and several important benefits, including:

• A complete inventory of all devices connected to the network;
• Information on critical access points, such as open ports;
• Detection of suspicious packets moving through the network;
• Real-time performance data displayed on dashboards;
• Comprehensive reports on the overall network status.

Scanning, which continually monitors the network, allows cybersecurity teams and administrators to find vulnerabilities early and respond swiftly, therefore protecting systems from hackers and other unwanted actors.

Essential Steps in Network Scanning

Most network scanning processes typically follow these steps:

Device Inventory

The scanning tool first surveys the network to detect and list all connected devices.

Network Topology Mapping

If supported, the tool generates a network topology map. Nmap (Network Mapper) scans ports to find devices and generates a network map. Nmap, an open-source tool, can scan large and complex networks, identifying active or inactive hosts and ports, and assessing perimeter defenses such as firewalls and intrusion detection systems.

Health and Vulnerability Assessment

The Address Resolution Protocol (ARP) checks network addresses, including primary and subnet levels, for irregularities. For broader analysis across geographic locations, the Internet Control Message Protocol (ICMP) is used. Advanced protocols may also be applied to collect detailed information about the network’s status and potential vulnerabilities.

Real-Time Monitoring and Reporting

Scanning findings are often shown on dashboards, delivering real-time information on network health, identified threats, and recommended mitigation strategies. Detailed reports can also be created for compliance and auditing needs.

Network Scanning Best Practices for Effective Security

To execute network scanning successfully, use the following practices:

1. Scan frequently: Schedule scans to uncover vulnerabilities before they may be exploited;
2. Use several tools: Use several scanning technologies to detect a broader variety of threats;
3. Focus on high-risk areas: Prioritize significant vulnerabilities and respond swiftly;
4. Ensure compliance: When doing network scans, follow industry standards and rules;
5. Continuous monitoring: Keep watch of network activities in order to detect anomalous behavior or potential threats;
6. Keep tools up to date: To discover new vulnerabilities, scan tools should be updated on a regular basis;
7. Scan internally and externally: Scan both within and outside the network to get a complete picture of potential dangers;
8. Control access: To avoid misuse, only authorized workers may run scans.

Choosing the Right Network Scanning Tools

A secure network is necessary for data exchange and resource management in any IT architecture. Network scanning helps to protect systems from abuse and security risks.

A variety of free and commercial network scanning tools are available, ranging from powerful port scanners to passive monitoring solutions. Choosing the appropriate technology necessitates a thorough assessment of your network’s requirements and possible vulnerabilities.

Key factors to evaluate when choosing a network scanning tool:

• Licensing costs (if applicable);
• Compatibility and adaptability with your network infrastructure;
• Overall cost estimation;
• User reviews and feedback;
• Quality of customer support;
• IP scanning policies;
• Availability of required features;
• Hardware and software requirements.

Top network scanning tools to consider:

• Auvik;
• Advanced IP Scanner;
• Angry IP Scanner;
• Intruder;
• ManageEngine OpUtils;
• Nikto;
• Nmap;
• OpenVAS;
• Perimeter 81;
• PRTG Network Monitor;
• Qualys Freescan;
• Retina Network Security Scanner;
• Syxsense;
• SoftPerfect Network Scanner;
• SolarWinds Network Device Scanner;
• Wireshark.

Key Advantages of Network Scanning

Network scanning offers several important benefits that contribute to better network security and performance:

Identifies Security Vulnerabilities

Network scanning examines active hosts and their interactions to detect weaknesses that could put sensitive data at risk. It helps uncover potential security gaps that may expose the network to cyber threats.

Detects and Prevents External Threats

One of the primary benefits is the ability to monitor existing network users and identify prospective entry points that attackers may use. Early discovery of these holes improves network security against unauthorized access.

Minimizes Manual Effort and Reduces Breach Costs

Automating network scans reduces errors, saves time, and improves accuracy compared to manual work. It also helps lower costs and limits the financial impact of potential breaches, even as cybersecurity tools become more expensive.

Enhances Network Performance

Routine scanning helps to correctly set up the network, discover vulnerabilities, and increase network availability. It also optimizes data flow, enhancing the speed of data transmission. Establishing robust baselines and mapping the network topology improves overall network performance.

Potential Risks of Network Scanning

While network scanning is vital for maintaining network health and security, improper or malicious use can introduce risks, including:

System Compromise

When attackers do scans, they can obtain information about open ports, services, and system data. This information might be used to exploit vulnerabilities and obtain unauthorized access.

Data Breaches

Once within the system, attackers can access sensitive data such as personal information, financial records, or secret corporate data, resulting in serious data breaches.

Unintentional Denial of Service

Excessive or poorly executed scanning may overload network resources, slowing down operations or causing systems to crash—resulting in temporary service disruptions.

Network Operation Disruptions

Intensive scanning requires large bandwidth and network resources, which can interrupt company operations, particularly in systems that rely significantly on network connection.

Conclusion

Network scanning is an important method for ensuring the security and performance of a network. It aids in the detection of vulnerabilities, the monitoring of network traffic, and the proper operation of systems. Regular scanning enables the early discovery of possible vulnerabilities, lowering the risk of cyberattacks and data breaches.

Organizations may increase their capacity to manage network resources, maintain system health, and satisfy security needs by adhering to best practices and employing reliable scanning technologies. A well-planned network scanning strategy is critical for securing sensitive data and keeping network operations running smoothly.