What Is Network Monitoring?

• Network Monitoring Definition

  Network Monitoring Definition

  Network monitoring is the process of continuously observing and analyzing a computer network's components, performance, and health to identify, diagnose, and resolve issues before they can negatively impact users or operations. It helps network administrators determine network performance and optimize network efficiency in real time.
• Key Aspects of Network Monitoring

  Key Aspects of Network Monitoring

  Poorly performing networks and devices compromise operations. Effective network monitoring is crucial to proactively identify, locate, and resolve issues quickly, thereby preventing costly outages and downtime.

  Key Aspects: 

  • Device Management: Monitoring critical network-connected devices (routers, switches, and servers) and their performance metrics is crucial for business continuity
  • Software Benefits: Network monitoring software gathers performance data, simplifies troubleshooting, reduces downtime, and offers comprehensive multi-vendor support; it also measures the overall health of the logical network
  • Functionality and the Open Systems Interconnection (OSI) Model: The core function of a network is information exchange, which is modeled by the OSI model; network monitoring provides essential visibility into every layer of the OSI model, allowing administrators to easily pinpoint and fix the root cause of network issues
• Types of Network Devices

  Types of Network Devices

  Core Network Devices:

  • Router: This device connects different networks (e.g., your local network to the internet) and determines the best path for data packets based on IP addresses; it primarily works at Layer 3 (Network ) of the OSI model
  • Switch: This component connects devices within a single network (LAN); it intelligently forwards data frames only to the intended recipient based on MAC addresses, operating at Layer 2 (Data Link)
  • Hub: This is a simple, largely obsolete connection point operating at Layer 1 (Physical); it broadcasts incoming data bits to all connected devices, which can cause network congestion

  Boundary and Security Devices:

  • Firewall: This device enforces security policies by monitoring and controlling incoming and outgoing network traffic; it acts as a barrier between a trusted internal network and untrusted external networks, operating across various OSI layers
  • Modem: This device converts digital signals from a computer into analog signals for transmission over lines (such as cable or phone lines) and vice versa, performing modulation and demodulation to connect your network to an ISP

  Connection and Signal Devices:

  • Access Point: This device allows wireless-enabled devices (laptops and phones) to connect to a wired network, and it functions at Layer 2 (Data Link)
  • Repeater: This device operates at Layer 1 (Physical) and amplifies or regenerates a network signal to extend its transmission distance, combating signal degradation
• Types of Network Monitoring Metrics

  Types of Network Monitoring Metrics

  To measure network performance, it’s important to understand and measure its metrics. Using network performance monitoring tools, you can gain insights into metrics such as jitter, latency, and packet loss. These metrics establish a baseline against which you can track results and improve the network's overall performance.

  • Latency: This is the round-trip time data packets take to reach their destination across a network; odd spikes represent major performance issues that may go unnoticed
  • Jitter: This is the variation in delay or disruption occurring when data packets travel across the organization's network; real-time applications such as video conferencing, faulty cables, and network congestion can cause jitter, affecting all network traffic
  • Packet Loss: This refers to the number of data packets lost in transmission over a network; measuring packet loss helps you determine the number of dropped packets to ensure data security and network performance
  • Throughput: This is the amount of data passing through a network from one place to another in a given amount of time; it’s a crucial metric to measure network performance
  • Packet Duplication: This refers to the duplication of packets while they’re moving in a network; it is identified when the same packet is received twice at its destination from the source
  • Packet Reordering: This is a network metric that determines the number of packets received in the wrong order; there can be several reasons for packet reordering, such as multi-path routing and route fluttering
• Types of Network Protocols

  Types of Network Protocols

  • Transmission Control Protocol (TCP): This is a standard communication protocol used to communicate over the network, enabling applications and communication devices to exchange information easily; it divides messages into a series of packets for easier transmission
  • File Transfer Protocol (FTP): This is a standard communication protocol used to exchange files and documents from the server to the client via a computer network; types of files can include text files, documents, and program files, and this protocol is built on a client–server model architecture
  • User Datagram Protocol (UDP): This is a communication protocol similar to TCP; it simplifies the way applications, services, and systems exchange information and can be used as an alternative to TCP and with IP as UDP/IP
  • Simple Network Management Protocol (SNMP): This is a networking protocol used to monitor and manage network-connected devices and applications, mainly in IP networks; it allows administrators to manage networks remotely with the help of the internet
  • Simple Mail Transport Protocol (SMTP): This is a set of communication guidelines or a protocol organizations can use to send electronic mail over their network via the internet
  • Hypertext Transfer Protocol (HTTP): This is a communication protocol designed to establish connections between servers by transferring hypertext; the protocol uses HTML tags to create links between servers
  • HTTP Secure (HTTPS): This protocol is designed to secure communications among servers or computers, and it can also be used to transfer data from the client browser to a web server using HTTP text or image; the data transmitted is encrypted
  • Internet Protocol (IP): This protocol is designed to assign unique IP addresses, and it’s commonly used with TCP; the unique IP addresses of data packets help them reach the correct destination via different nodes in a network
• Main Benefits of Network Monitoring

  Main Benefits of Network Monitoring

  • Stay Ahead of Outages: Manual errors, configuration issues, and environmental factors can contribute to network issues, and implementing network monitoring can provide the visibility you need to stay ahead of potential problems. It enables you to track and monitor live network performance data in an easy-to-read interface.
  • Fix Issues Faster: Monitoring your network can help reduce outages. Whether you have a configuration or traffic-related issue, it can help you quickly identify errors and performance outages through live network maps. This ability to automate root cause analysis drastically speeds up resolution time.
  • Reduce Complexity: With technology innovation and the rise in connected devices, modern enterprises rely heavily on the internet for several business-critical tasks. Internet-dependent services may include ISPs, service providers, content delivery networks, software as a service, and VPNs. Each of these services operates over the internet, making the network susceptible to performance fluctuations and routing issues. Having proper visibility into your network early on can help reduce the chances of errors.
  • Enhance Network Security Posture: Network monitoring continuously watches traffic patterns and device behavior, allowing it to detect unusual or suspicious activity that may indicate a security threat or breach, such as an unauthorized access attempt, a sudden spike in traffic volume resembling a distributed denial of service attack, or a device attempting to communicate with known malicious IP addresses. By getting real-time alerts on these anomalies, you can isolate and mitigate threats before they compromise data or disrupt operations.
  • Optimize Resource Allocation (Capacity Planning): Network monitoring provides historical data on resource utilization, including bandwidth consumption, CPU load on servers, and data center usage over weeks or months—data vital for capacity planning. By analyzing trends, the monitoring solution is highly scalable—it efficiently handles data collection from thousands of endpoints—and helps you predict when key components will reach their limits, allowing you to purchase and deploy upgrades (e.g., more bandwidth, faster routers, or additional servers) before performance degradation occurs. This prevents inefficient over-provisioning or critical under-provisioning of resources.
• The Five Basic Functions of Network Monitoring Tools

  The Five Basic Functions of Network Monitoring Tools

  1. Discover: Finding Devices on Your Network

  The Discovery function is the initial and crucial step for any monitoring tool. It involves automatically scanning the network to locate and identify all connected devices, applications, and services.

  • How It Works: The tool uses protocols such as SNMP, ICMP (Ping), and Address Resolution Protocol to probe IP address ranges defined by the administrator
  • Purpose: It creates a complete, up-to-date inventory of your IT assets, including routers, switches, servers, printers, and VMs, ensuring the monitoring system knows exactly what needs to be watched

   

  2. Map: Visualizing Your Network

  Once devices are discovered, the Map function processes the connectivity data to create a visual representation of the network topology.

  • How It Works: The tool analyzes the connections between devices (often by reading the forwarding tables of switches and routers) and renders a network topology map
  • Purpose: This provides administrators with a logical and often hierarchical view of the infrastructure, making it much easier to identify bottlenecks, trace data paths, and pinpoint the physical location of an issue

   

  3. Monitor: Keeping an Eye on Your Network

  The Monitor function is the continuous, real-time collection and analysis of performance metrics and status data from all discovered devices.

  • How It Works: The tool periodically polls devices (via SNMP, WMI, or agents) to collect metrics such as CPU utilization, memory usage, NetFlow, interface traffic volume, latency, and error rates
  • Purpose: It tracks these metrics against historical data (baselines) to determine the current health and performance of the network, ensuring devices and links are operating within expected parameters

   

  4. Alert: Getting Notifications When Devices Go Down

  The Alert function provides immediate notification when a significant network event or performance degradation occurs, ensuring administrators can react quickly.

  • How It Works: Administrators set thresholds (e.g., “Alert me if server CPU usage exceeds 90% for more than 5 minutes” or “Alert me if the device cannot be pinged”), and when a monitored metric crosses a set threshold, the system triggers an alert
  • Purpose: It transforms passive monitoring data into actionable notifications, allowing for proactive troubleshooting to prevent issues from escalating into full network outages or critical failures; alerts are typically sent via email or SMS or displayed on a central dashboard

   

  5. Report: Delivering on Service Level Agreements With Real-Time Reporting

  The Report function provides historical and real-time summaries of network performance data, allowing for analysis, auditing, and future planning.

  • How It Works: The tool aggregates the collected monitoring data over time and presents it in customizable views, graphs, and summary documents; reports can cover uptime, device availability, bandwidth consumption trends, and service level agreement (SLA) compliance
  • Purpose: Reporting is crucial for capacity planning (understanding when upgrades are needed), auditing (demonstrating security and compliance), and proving the network is meeting defined SLAs with customers or internal departments

  Monitoring solutions use standard protocols such as SNMP, IP, and TCP to poll network devices and servers and send updated real-time performance data. These solutions also provide multi-vendor network monitoring that scales and expands as your network grows. They offer network availability monitoring, critical path visualization, intelligent mapping features, performance analysis, and advanced alerting features.