Network Topology map tells you what’s on your network, where it is and how it is connected. Created automatically, it can be searched, filtered and is automatically updated. Learn more about real-time maps and dynamic views that NetCrunch provides and their most common usage scenarios

About Network Topology Mapping

There are several reasons for mapping network topology, some more common than others. For starters, they typically incorporate a vast array of important information about your network. They will, for instance, tell you what each piece of equipment is, how everything is interconnected, and they will often include extra details such as IP addresses, traffic speed or volume, or other configuration parameters.

A network topology map diagram is also an invaluable troubleshooting tool that you’ll be glad you have when something is wrong. Let’s say, for example, that there is a report of poor performance between a workstation and a server. A network topology diagram would quickly let you figure out what devices are on the path, to what port on which switch they are connected, giving you a starting point for troubleshooting.

Good documentation is the best way to keep track of everything and manage network capacity and growth requirements. To achieve it, maps need to be constantly updated and reviewed regularly to identify bottleneck or underutilized resources.

Network Topology Mapping Tools

Topology mapping tools typically do much more than just help you draw network topology maps — or draw them for you. The better ones will use SNMP and/or other protocols such as the Cisco Discovery Protocol (CDP) to poll your devices and discover their interconnections. They will use that information to automatically build a graphical representation of your network, a network topology map.

These tools can save you a tremendous amount of time documenting your network’s topology. Some tools will also integrate with network monitoring tools and will overlay live information over the topology maps that they build. But for the very best integration, you should pick a tool that offers both monitoring and topology mapping in one package.

The more advanced network topology mapping tools are more closely related to management tools more than documentation tools. You can use them to not only display your network topology but also to monitor devices’ status and performance. Some higher-end tools will even allow you to manage devices right from within them.

Mapping Network Topology With NetCrunch

Live Network Views

Most NetCrunch views are “live” and they are updated in real-time. They can also be automatically arranged. Layer 2 segment maps display port status and current traffic and monitoring dependencies display a diagram of dependencies discovered through router and switch connections. There are also custom maps with widgets that can display the status of network objects (nodes, interfaces, services, alerts, etc.) as well as performance metrics.

Layer 2 Topology Mapping

This is an important feature of NetCrunch. The module, which is part of NetCrunch Suite and NetCrunch for Network Infrastructure and can be added to any NetCrunch product, will discover and display the physical connections between switches and nodes on the automatic layer 2 topology maps. It allows for the automatic presentation of switch connections, traffic volume and speed, and bandwidth usage, it has built-in support for EtherChannel and VLANs.

Graphical Map Widgets

Graphical network maps are a vital element of network visualization. While most network monitoring tools use a tile-based dashboard, NetCrunch’s maps show relations between components as well as their location. They can contain multiple elements allowing for the visualization of network object status and performance data widgets for displaying current performance metric values.

Automatic update of views and maps

The automation that is built into NetCrunch’s topology maps is one of its best features, Networks are in constant evolution with new devices and new circuit regularly added. This makes it hard to maintain up-to-date static network diagrams. Using NetCrunch’s layer 2 topology mapping feature, maps are automatically updated whenever a new node is added or a connection changes. The maps are also active and they display the status of each device, while connections between switches show actual bandwidth usage. These maps will help you easily spot network problems and quickly drill down to the problematic device or circuit. Their visual presentation makes it easy to understand the relationship between parent and dependent devices on your network.

Switch port mapping

NetCrunch’s Segment Maps displays the connections on each switch port. Each line on the map presents current in/out traffic on the port. The connections are clickable to reveal the real-time traffic graph of any given port. Alternatively, you can also visualize traffic history. They can display summary traffic by volume over the last hour or last 24 hours, or simply the current status of the connections. In situations where multiple devices are connected to a single switch port and NetCrunch can’t access switch or router data, the software will build a static map without traffic data and port information. This mostly happens when non-manageable devices are discovered.

Wrapping Up

While network topology mapping can be complex — especially if you do it manually — it is one of the very best ways of documenting networks. Due to its graphic nature, a network topology map presents information in a very easy to comprehend format. Any network administrator or engineer will get much more benefit from a map from any kind of textual data. With the availability of very efficient network topology mapping tools, such as those built into NetCrunch, the mapping network topology can be automated. This not only makes it easier for administrators, but it also offers a dynamic rendition of the network that will be automatically updated as your network evolves. Add to that the possibility of overlaying live usage data on topology maps and you clearly have a winning combination.

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