How Network Monitoring Works, What to Monitor, and Tips for Success

What Is Network Monitoring? 

Network monitoring involves observing and analyzing network performance and health through various devices and software tools. This process aims to ensure the smooth operation of network infrastructure by tracking data flows, device statuses, and potential faults that may disrupt service. 

Network administrators often leverage these insights to manage bandwidth, detect anomalies, and enable proactive maintenance activities, reducing downtime and mitigating risks associated with network issues.

Network monitoring tools collect data using protocols such as SNMP (simple network management protocol) and ICMP (internet control message protocol), enabling administrators to assess the network’s state in real time. These tools often provide graphical interfaces that display metrics like packet loss, latency, and uptime, making it easier to understand network conditions. 

This is part of a series of articles about network security.

The Importance of Network Monitoring 

There are several reasons that organizations must implement network monitoring strategies.

Early Detection of Network Issues

Early detection of network problems involves continuously scanning network activity to spot irregularities. These irregularities may include unusual traffic volumes, unexpected downtime, or equipment malfunction. Network administrators can quickly intervene by detecting these issues early, addressing the root cause before it disrupts networks. This saves time and resources from prolonged troubleshooting.

Early detection can prevent security breaches by identifying potential threats as they arise. For example, sudden spikes in data transfer may indicate unauthorized access or data exfiltration attempts. With real-time alerts and reporting, network monitoring systems can notify administrators of these anomalies, enabling a rapid response to mitigate security risks promptly.

Ensuring Network Performance and Availability

By tracking key performance metrics, such as bandwidth utilization and latency, network administrators can ensure resources are used efficiently and avoid potential bottlenecks. Consistent monitoring provides insight into network health, enabling timely upgrades or reallocations to maintain connectivity across the organization.

Additionally, network monitoring supports high availability by promptly alerting teams to failures or degradations in network components. These alerts allow for swift action, minimizing downtime and maintaining service availability.

Compliance and Security Monitoring

Compliance and security are significant concerns addressed by network monitoring systems. These systems track access logs, user activities, and data transfers, ensuring that network use aligns with regulatory standards and organizational policies. Monitoring can help identify compliance gaps, enabling companies to take corrective measures promptly to avoid penalties.

Security monitoring focuses on identifying and responding to potential threats, such as unauthorized access and malware intrusion. Real-time network monitoring detects deviations from established security norms, triggering alerts to enable immediate response. This strengthens the organization’s defense against cyber threats, protecting sensitive data.

Key Components of Network Monitoring Systems 

Data Collection Methods

Data collection involves gathering information on network traffic, device status, and performance metrics. Traditional methods include SNMP, which collects and organizes data regarding network devices, and ICMP probes, which measure connectivity and response times. These tools work collectively to create a detailed network overview, guiding administrators to make informed decisions when optimizing performance or troubleshooting issues.

Data collection techniques also utilize flow-based technologies like NetFlow and sFlow, which offer granular visibility into network traffic patterns and bandwidth usage. These methods provide invaluable insights into application performance and user behavior, helping to identify bottlenecks or unauthorized data usage.

Network Topology and Mapping

Network topology and mapping are critical components in network monitoring, providing a visual representation of how devices and connections are organized within the network. This graphical depiction allows network administrators to better understand how traffic flows between devices, identify potential single points of failure, and assess the impact of outages on the network. 

Accurate topology mapping aids in efficient troubleshooting and optimizing network paths. Network mapping tools automatically detect and document changes in the network environment, maintaining up-to-date topology representations. As networks evolve with new devices and technologies, dynamic mapping supports integration and visibility.

Alerting and Reporting Mechanisms

Alerting and reporting mechanisms are indispensable in network monitoring, providing real-time notifications of anomalies or failures. Alerts are configured to trigger for specified thresholds, such as increased latency or device disconnects. When these conditions are met, alerts are sent to network administrators, prompting immediate investigation and resolution.

Reporting features complement alerting systems by providing insights into long-term trends and performance metrics. Regularly generated reports help identify patterns that may suggest underlying issues or opportunities for optimization. They also support compliance by documenting network activities and demonstrating adherence to regulatory standards.

Tips from the expert

Steve Moore is Vice President and Chief Security Strategist at Exabeam, helping drive solutions for threat detection and advising customers on security programs and breach response. He is the host of the “The New CISO Podcast,” a Forbes Tech Council member, and Co-founder of TEN18 at Exabeam.

In my experience, here are tips to help you optimize your network monitoring strategies for enhanced performance and security:

1. Leverage AI and machine learning for predictive analytics: Use AI-powered monitoring tools to analyze historical data and predict potential failures or bottlenecks. This approach helps address issues before they impact network performance.
2. Segment networks for enhanced visibility: Divide the network into logical segments (e.g., by department or application) to focus monitoring efforts and pinpoint issues faster. Segmentation also enhances security by limiting the scope of potential threats.
3. Use flow-based monitoring alongside traditional metrics: Incorporate tools like NetFlow or sFlow to analyze traffic flows for deeper insights into bandwidth usage, application performance, and anomalous behavior. This complements SNMP-based monitoring for a more comprehensive view.
4. Implement time-based thresholds for alerts: Set dynamic thresholds for performance metrics based on time-of-day trends. For example, configure higher bandwidth thresholds during peak business hours to reduce false positives and focus on truly anomalous activity.
5. Combine on-premises and cloud-based monitoring tools: Use hybrid solutions to gain visibility across traditional and cloud infrastructures. Tools that integrate across environments are essential for monitoring hybrid or multi-cloud networks.

Network Monitoring Metrics and Protocols

Common Metrics Monitored

Effective network monitoring hinges on tracking metrics that reveal the health, performance, and reliability of the network. Commonly monitored metrics include:

1. Bandwidth utilization: This metric shows how much of the available network bandwidth is being used at a given time. High utilization may indicate network congestion, requiring resource reallocation or upgrades.
2. Latency: Latency measures the time it takes for data to travel from its source to its destination and back. High latency affects real-time applications like VoIP and video conferencing, necessitating timely intervention to improve user experience.
3. Packet loss: Packet loss refers to the percentage of data packets that fail to reach their destination. Even small amounts of packet loss can disrupt applications sensitive to data delivery, such as streaming or online gaming.
4. Uptime and downtime: Monitoring device and service uptime provides insights into the reliability of network components. Frequent or extended downtime can signal failing hardware, software misconfigurations, or broader infrastructure issues.
5. Error rates: This metric tracks the number of errors in transmitted data, such as collisions, dropped packets, or retransmissions. High error rates often point to issues like hardware failure or poor cabling.
6. Throughput: Throughput measures the actual data transfer rate across the network. Discrepancies between throughput and bandwidth utilization may signal performance issues like bottlenecks or interference.
7. Jitter: Jitter refers to the variation in packet delivery times. This metric is particularly important for real-time applications, as excessive jitter can lead to poor quality in voice and video communication.
8. CPU and memory usage on devices: Monitoring resource usage on network devices like routers, switches, and servers helps prevent performance degradation due to overloaded hardware.
9. Connection status: Regularly checking the status of connections between devices ensures all components remain operational. Detecting downed connections quickly minimizes service disruption.

SNMP (Simple Network Management Protocol)

SNMP is a critical protocol in network monitoring, enabling the collection and management of network data across diverse devices. It operates by querying devices for information, such as performance metrics and alerts, enabling centralized network management. Through its widespread adoption and compatibility with many devices, SNMP aids monitoring efforts.

SNMP’s architecture, consisting of agents, managers, and management information bases (MIBs), forms a structured approach to data retrieval and management. SNMP agents run on network devices, reporting to SNMP managers, which process and analyze the data. MIBs define the data structure, providing standards for what information is available and how it is accessed.

NetFlow and sFlow

NetFlow and sFlow are technologies used to provide network visibility and traffic analysis by capturing packet flows. NetFlow, developed by Cisco, collects IP traffic data and provides information about source, destination, volume, and paths taken within the network. This visibility allows for in-depth traffic analysis, identifying trends, usage patterns, and anomalies.

sFlow is a packet sampling technology that provides a statistical representation of data traversing a network. It is efficient in monitoring high-speed networks where capturing all packets may not be feasible. sFlow offers insights into both Layer 2 and Layer 3 traffic, making it versatile for network visibility. 

ICMP (Internet Control Message Protocol)

ICMP aids in network diagnostics and monitoring by providing feedback about connection-related issues. It is primarily used for error reporting, enabling message exchange between devices to indicate network connectivity problems, such as unreachable destinations. Utilities like ‘ping’ and ‘traceroute’ rely on ICMP to test host reachability and trace network paths.

Despite its utility, ICMP can also pose security risks if exploited for denial-of-service attacks or network reconnaissance. Therefore, while ICMP is integral in performance monitoring, its usage must be carefully managed and secured within networks.

Types of Networks and Devices Monitored 

Routers, Switches, and Hubs

Routers, switches, and hubs are primary network devices, enabling data transmission. Routers manage traffic between different networks, necessary for connecting local networks to the internet. Monitoring routers ensures addressing potential bottlenecks and optimizing routing paths for efficient traffic flow. This involves tracking metrics like throughput, latency, and error rates to maintain connectivity and performance.

Switches enable communication within a network by directing data to specified devices, achieving efficient data distribution. Monitoring switches helps in identifying port status, bandwidth utilization, and collision rates to prevent performance degradation. Hubs, although simpler in function, act as basic connectors within networks. Monitoring them is essential for identifying potential faults affecting network segments.

Firewalls and Security Devices

Network security devices, including firewalls, form a critical defense against cyber threats and unauthorized access. Monitoring these devices ensures they function effectively in enforcing policies and blocking harmful traffic. Key metrics such as attempted attacks, access violations, and traffic patterns are scrutinized to detect and respond to security incidents promptly.

Additionally, monitoring solutions enable compliance by logging access attempts and configuration changes on security devices. This level of visibility aids in forensic analysis following a security breach, swiftly identifying compromised systems or policy violations.

Servers and Virtual Machines

Monitoring servers and virtual machines aids in maintaining service continuity and performance. Servers host applications and data vital to business functions, requiring close monitoring of CPU usage, memory consumption, and disk I/O. These metrics reveal potential overutilization or hardware failures, guiding timely maintenance actions to avert unscheduled downtime.

Virtual machines introduce particular monitoring needs due to their scalable and transient nature. Metrics like resource allocation, virtual CPU load, and network usage become critical in optimizing the virtual environment. By ensuring virtual assets are effectively monitored, organizations can dynamically adapt resources to meet demands.

Cloud Infrastructure and Services

With their distributed and scalable infrastructure, cloud services require monitoring solutions that provide visibility into resource allocation, availability, and performance across multiple regions. Key metrics such as response times, service uptime, and access logs are crucial for ensuring the cloud environment performs reliably and remains secure.

Monitoring cloud services also enables proactive resource management, ensuring virtual instances scale during peak loads without deteriorating performance. Additionally, monitoring supports cost management by identifying underutilized resources or unnecessary expenses.

Wired and Wireless Networks

Wired networks demand monitoring of components like Ethernet switches and cables, focusing on connection integrity and throughput to prevent disruptions. Wireless networks involve unique challenges like signal interference, channel congestion, and coverage area assessment. Monitoring these aspects is crucial for maintaining wireless performance.

Wireless network monitoring collects data on user devices and access points, helping identify connectivity issues or unauthorized access attempts. By analyzing signal strengths and data transfer rates, administrators can optimize wireless network configurations to achieve improved coverage and user experiences.

Related content: Read our guide to monitor network devices

Challenges in Network Monitoring 

Organizations must be aware of the factors complicating network monitoring.

Monitoring in Hybrid and Multi-Cloud Environments

Hybrid and multi-cloud environments introduce layers of complexity to network monitoring, demanding solutions that address diverse infrastructure and integration challenges. These environments span private and public cloud instances and on-premises systems, requiring tools capable of delivering consistent performance views across all components. 

The dynamic nature of cloud environments means monitoring solutions must adapt to rapid scaling and changes without disrupting visibility. This requires flexible architectures and automated discovery features to keep pace with evolving infrastructure.

Handling Large Volumes of Data

The sheer volume of data generated in modern networks can be overwhelming, posing significant challenges for monitoring systems tasked with processing and analyzing this information. Efficiently managing and filtering massive data flows is essential to deriving actionable insights without overburdening system resources.

Ensuring data integrity and accuracy is crucial for reliable monitoring outcomes. Inaccurate or incomplete data hampers decision-making capabilities, leading to incorrect diagnoses or missed alerts. 

Ensuring Network Security and Compliance

Effective monitoring requires implementation strategies that enforce security policies and protect data during transit and storage. Advanced encryption and access controls are necessary to secure monitoring processes and ensure compliance with regulations like GDPR and HIPAA.

It is also important to have records to provide evidence of adherence to security standards and regulatory requirements, supporting audit processes.

5 Best Practices for Effective Network Monitoring 

Here are some of the ways that organizations can ensure effective monitoring of their networks.

1. Define Clear Monitoring Objectives

Objectives may focus on maintaining uptime, detecting anomalies promptly, or optimizing resource use. By establishing precise objectives, organizations can tailor their monitoring strategies to deliver meaningful insights and support strategic decision-making.

This clarity also ensures effective resource allocation and helps set realistic performance metrics and benchmarks. With well-defined monitoring objectives, teams can prioritize key activities and develop targeted action plans.

2. Regularly Update Network Documentation

Consistently updating network documentation ensures that all changes to infrastructure are accurately reflected, supporting effective monitoring and intervention efforts. Documentation should detail topology, device configurations, and dependencies, offering a reference for administrators managing the network. Regular updates enable accurate tracking of assets, configuration changes, and network growth over time.

Comprehensive documentation aids in troubleshooting by quickly identifying affected areas during incidents. It also supports compliance efforts, proving adherence to security policies and procedures.

3. Implement Proactive Alerting and Incident Response

Proactive alerting and incident response enable swift action when performance issues or security threats arise. Configuring alert thresholds based on historical data trends allows administrators to detect anomalies before they escalate into significant problems. These alerts support agile incident response by providing actionable insights that guide targeted remediation efforts.

Incident response protocols complement proactive alerting, detailing steps for diagnosis, escalation, and resolution. These protocols ensure that issues are addressed promptly, minimizing downtime and impact on operations.

4. Perform Routine Network Assessments and Audits

Routine network assessments and audits provide insights into network performance and security posture. These evaluations identify areas for improvement, uncovering vulnerabilities or inefficiencies that may impede operations. Audits systematically review network configurations, policies, and procedures, ensuring alignment with best practices and regulatory requirements.

Regular assessments also help measure the success of monitoring strategies, enabling the ongoing refinement of tools and processes.

5. Train Staff on Monitoring Tools and Procedures

Training staff on the use of network monitoring tools and procedures is crucial for maximizing the capabilities of monitoring systems. Well-trained teams can interpret data accurately, recognize anomalies, and take informed actions to resolve issues promptly. Regular training ensures staff stay updated on new monitoring features and methodologies.

Training also encourages collaborative efforts across IT teams, fostering a shared understanding of monitoring objectives and practices. This improves communication and coordination during incident response, driving more efficient and effective resolution processes.

Exabeam: Quickly Gain Visibility into Your Entire Environment​ with NetMon

Network monitoring can also play an essential role in detecting, neutralizing, and recovering from cyberattacks. SOC teams need full visibility into their organization’s networks to detect these threats, perform proper forensic investigations, support audits, and identify operational issues. NetMon adds an additional, powerful layer to your security stack. Available as an appliance or a virtual machine in your network infrastructure or an add-on to your Exabeam deployment, NetMon delivers more detailed network visibility than next-generation firewalls, intrusion detection systems/intrusion prevention systems (IDS/ IPS), or other common network equipment. 

Detect advanced threats with market-leading application recognition, script-based analytics across network and application data, and rich data for centralized scenario-based analytics. Immediately capture, analyze, and record network traffic, leveraging NetMon dashboards for powerful and insightful information about your network​. And take your investigation further with Deep Packet Analytics (DPA). DPA builds on the NetMon Deep Packet Inspection (DPI) engine to interpret network traffic, including immediate recognition of PII, credit card information, port and protocol mismatch, and other key indicators of compromise (IOCs). DPA allows for continuous correlation against full packet payloads and metadata using prebuilt and custom rule sets and provides unprecedented control over alarming and response at the flow and packet level. Through DPA rules, your SOC can automate threat detection that was previously only possible via manual packet analysis.

By tying together firewall data, network monitoring, user activity, and automated detection, Exabeam empowers security teams to move beyond alerts to actionable intelligence, ensuring faster, more accurate threat detection, investigation, and response (TDIR).

Learn more about NetMon