Prtg: Easy Switch Interface Bandwidth Monitoring

Monitoring switch interface bandwidth is a crucial aspect of network management. It helps identify potential issues, optimize resource allocation, and enhance network security. PRTG offers comprehensive switch monitoring capabilities, including the ability to track switch ports, hardware health, bandwidth usage, and more. With preconfigured sensors for major manufacturers, PRTG makes it easy to set up switch interface bandwidth monitoring. This paragraph introduces the topic of how to add a switch interface bandwidth monitoring in PRTG and highlights its importance in maintaining efficient and secure network operations.

Using SNMP Traffic Sensors

SNMP, or Simple Network Management Protocol, is the most basic method of gathering bandwidth and network usage data. It is a set of standards for communication with devices in a TCP/IP network. SNMP monitoring is useful for those who are responsible for servers and network devices such as hosts, routers, hubs, and switches. It is also the most commonly used method because it requires minimal bandwidth and CPU cycles.

To use SNMP for monitoring purposes, the User Datagram Protocol (UDP) packets must be able to be bidirectionally sent from the PRTG core server to the target device. This is usually the case in LANs and intranets. For connections across the internet, to a perimeter network, or for WAN connections, some changes to the traversed firewalls might be necessary.

PRTG supports three versions of the SNMP protocol: version 1, 2c, and 3. The first is the oldest and most basic version, supported by most SNMP-compatible devices. However, it has limited security because it only uses a simple password and sends data in clear text. SNMP v2c adds 64-bit counters, which are useful for monitoring bandwidth usage in networks with gigabits/second loads, but it also has limited security. SNMP v3 adds authentication and encryption, offering user accounts and optional data packet encryption to increase security. However, it is difficult to configure and has a higher overhead for the probe, reducing the number of devices that can be monitored.

When using SNMP Traffic Sensors, it is recommended to monitor core layer switches in a very detailed way, the distribution layer in a detailed way, and to focus on monitoring the uplinks on the access layer switches. To set up the sensors, first choose the router or switch you want to monitor from the device tree. Then, right-click the respective device and select 'Add Sensor' from the context menu. In the 'Add Sensor' dialog, select 'Bandwidth/Traffic' under 'Monitor What?' and then select the SNMP Traffic sensor. It is recommended to start with the default settings, which can be changed at any time.

The SNMP Traffic Sensor is particularly useful for Cisco switch monitoring. It allows you to monitor the incoming and outgoing traffic on your Cisco switch, helping you to identify and troubleshoot issues before they become emergencies.

Monitoring Cisco Switches

##section 1: Understanding the Importance of Monitoring Cisco Switches

Cisco switches play a crucial role in connecting multiple devices within a network infrastructure. By monitoring these switches, administrators can:

• Ensure optimal network performance by identifying and resolving bottlenecks.
• Enhance network security by detecting unauthorized devices or activities.
• Facilitate proactive troubleshooting by detecting issues early on.
• Optimize resource utilization through capacity planning and trend identification.

Section 2: Choosing the Right Monitoring Tools

When selecting a Cisco switch monitoring tool, consider the size of your network and your specific requirements. Some popular tools include:

• Paessler PRTG: Offers specialized sensors for Cisco devices, SNMP and Netflow integration, and customizable parameters.
• SolarWinds Network Insights for Cisco ASA Monitoring: Provides continuous monitoring and performance analysis for Cisco ASA devices, reducing the need for manual troubleshooting.
• Cisco Network Assistant: A free tool from Cisco for managing up to 80 devices, with an intuitive GUI, automatic network discovery, and real-time alerts.
• Datadog Network Monitoring: A cloud-based service with customizable data screens, real-time data visualizations, and topology mapping.

Section 3: Implementing Monitoring with Paessler PRTG

In this example, we'll use Paessler PRTG to set up Cisco switch monitoring:

• Install and set up PRTG: PRTG offers a quick installation process and automatic network discovery to create your initial monitoring setup.
• Utilize preconfigured sensors: PRTG comes with preconfigured sensors for Cisco switches, speeding up the setup process.
• Monitor key metrics: Track CPU usage, temperature, uptime, data traffic, switch ports, and more.
• Set up custom alerts: PRTG allows you to receive real-time alerts via SMS, email, or push notifications when specific conditions are met.
• Visualize data: PRTG provides clear graphs and dashboards to help you identify problems and troubleshoot issues effectively.
• Monitor your entire network: With PRTG, you can monitor not just Cisco switches but also network devices from other manufacturers, ensuring comprehensive visibility.

Section 4: Best Practices and Recommendations

To optimize your Cisco switch monitoring:

• Monitor core layer switches in detail, with a focus on distribution and access layer switches.
• Utilize SNMP Traffic sensors to measure bandwidth usage on specific ports.
• Leverage NetFlow sensors for in-depth traffic analysis on individual ports.
• Take advantage of PRTG's reporting engine to generate ad-hoc or scheduled reports in various formats.
• Explore PRTG Maps to create customized dashboards for different stakeholders.

Switch Port Monitoring

Reasons to Choose PRTG for Switch Port Monitoring:

PRTG offers several advantages for switch port monitoring:

• Compatibility: PRTG is compatible with almost all switch manufacturers, including Cisco, Linksys, Netgear, and Yamaha. This ensures that you can monitor switches from various vendors seamlessly.
• Security Enhancement: With PRTG, you can instantly see if a switch port is open. This helps in closing gateways to prevent brute-force attacks or malware infiltration, significantly bolstering your network security.
• Instant Alerts: PRTG provides customizable notifications to alert you of any switch issues or malfunctions. You can choose to be notified via SMS, email, push notification, or other methods, allowing for prompt troubleshooting.
• Comprehensive Hardware Monitoring: PRTG allows you to monitor various hardware components, such as servers, routers, firewalls, and switches. This includes tracking hardware health, status, bandwidth utilization, Wi-Fi traffic, applications, and services.
• Trend Identification and Optimization: PRTG helps you analyze which applications generate the most traffic and where bottlenecks occur. This enables you to optimize bandwidth allocation and improve overall network performance.
• Visual Data Representation: PRTG visualizes monitoring data through clear graphs, topology maps, and dashboards. This makes it easier to identify problems and troubleshoot your switches efficiently.

Preconfigured Sensors for Switch Port Monitoring:

PRTG offers preconfigured sensors to simplify switch port monitoring:

• SNMP Sensors: PRTG includes preconfigured SNMP sensors for switches from well-known manufacturers. For instance, the SNMP Cisco System Health sensor and the SNMP Dell Hardware sensor.
• Packet Sniffer Sensor: This sensor monitors the headers of data packets passing through a local network card, filtering traffic by IP address, protocol, and data type.
• Flow Sensors: You can monitor traffic on switches from manufacturers like Cisco and Juniper using preconfigured Flow sensors, such as NetFlow v9, jFlow v5, or sFlow (Custom) sensors.

Steps to Configure Switch Port Monitoring:

To configure switch port monitoring in PRTG, follow these general steps:

• Identify the Switch: In the PRTG interface, navigate to the device tree and select the switch you want to monitor.
• Add a Sensor: Right-click on the selected switch and choose "Add Sensor" from the context menu.
• Select Bandwidth/Traffic Sensor: In the "Add Sensor" dialog, choose "Bandwidth/Traffic" under "Monitor What?" This will allow you to monitor the bandwidth utilization and traffic flow through the switch ports.
• Choose the Appropriate Sensor Type: Depending on your switch manufacturer and specific requirements, select the appropriate sensor type. For example, the SNMP Traffic sensor, Packet Sniffer sensor, or Flow sensors (NetFlow, jFlow, sFlow, or IPFIX).
• Customize Sensor Settings: Start with the default settings, which can be modified later as needed.
• Visualize and Analyze Data: PRTG provides visual representations of your monitoring data, including graphs, toplists, and dashboards. Use these tools to identify traffic patterns, bottlenecks, and potential issues.
• Set Up Custom Alerts: Configure customizable alerts to notify you about bandwidth shortages, bottlenecks, or other issues. This enables proactive troubleshooting before problems become critical.

Additional Tips:

• It is recommended to monitor core layer switches in detail, while focusing on monitoring the uplinks for access layer switches.
• PRTG's auto-discovery feature can automatically detect and add devices from your network, making the initial setup process quicker and easier.
• For Cisco switches, PRTG offers specific sensors like the NetFlow sensors and the SNMP Cisco System Health sensor.

Bandwidth Monitoring Methods

Bandwidth monitoring is a critical aspect of managing and maintaining network performance. There are several methods and tools available to monitor bandwidth usage and performance. Here are some common bandwidth monitoring methods and their key features:

Simple Network Management Protocol (SNMP):

SNMP is a standard protocol used to manage and monitor network devices. It can be used to gather basic bandwidth usage data port by port. SNMP Traffic sensors can be used to measure the bandwidth used by a specific device or a specific port on a switch or router. This method is suitable for monitoring core layer switches, distribution layer switches, and uplinks on access layer switches.

Flow-based Monitoring (NetFlow, IPFIX, jFlow, sFlow):

Flow technologies are best suited for enterprise-grade routers and switches from Cisco, Juniper, HPE, and other manufacturers. Flow monitoring is ideal for larger networks where identifying bottlenecks and consumption by IP address is necessary to troubleshoot bandwidth issues. Flow sensors can be used to monitor traffic by protocol or IP address. This method is recommended for high-traffic networks and advanced users.

Packet Sniffing:

Packet sniffing involves inspecting every single network data packet that passes through a network card or a monitoring port of a switch. PRTG's Packet Sniffer sensor can be used for packet sniffing-based bandwidth monitoring. This method is suitable when network devices do not support SNMP or Flow protocols, or when differentiating bandwidth usage by network protocol or IP address is required. However, packet sniffing creates the highest CPU load on the system running PRTG.

Windows Management Instrumentation (WMI):

WMI is a Microsoft technology used to monitor and manage Windows-based systems. While not originally intended for bandwidth monitoring, WMI can be used for this purpose. The Windows Network Card sensor in PRTG, for example, monitors bandwidth usage and traffic on a network interface via WMI. Monitoring bandwidth via WMI has a moderate impact on system performance.

By utilizing these methods and tools, network administrators can effectively monitor and optimize their network bandwidth usage, identify bottlenecks, and ensure efficient network performance.

Pre-configured Sensors

PRTG comes with pre-configured sensors for major manufacturers such as Cisco, HPE, Juniper, and Dell, which speeds up the setup process. There are also around 20 pre-configured sensors for bandwidth monitoring that can be set up with just a few clicks.

The SNMP Traffic Sensor with the Connection Status Handling configured, for example, can alert you when a sensor for the interface will always turn into a red error status for a disconnected interface. The sensor will go into an error status for a disconnected interface only if it is not deliberately deactivated in the configuration.

The Packet Sniffer sensor monitors the headers of data packets that pass a local network card using a built-in packet sniffer, and filters the traffic by IP address, protocol, and data type.

The Flow (NetFlow, jFlow, sFlow, IPFIX) sensors can be used to monitor the traffic on switches from manufacturers such as Cisco and Juniper using pre-configured NetFlow v9, jFlow v5, or sFlow (Custom) sensors.

The SNMP Cisco System Health sensor and the SNMP Dell Hardware sensor are also pre-configured SNMP sensors for the switches of well-known manufacturers.

Frequently asked questions