Network topology is the way a network is arranged, including the physical or logical description of how the links and nodes are set up to relate to each other. There are numerous ways a network can be arranged, all with different pros and cons, and some are more useful in certain circumstances than others.
Several tasks go into effective network topology management, including configuration management, visual mapping, and general performance monitoring. The key is to understand your objectives and requirements to create and manage the network topology in the right way for your business.
Why Is Network Topology Important?
The way a network is arranged can make or break network functionality, connectivity, and protection from downtime. The question of, “What is network topology?” can be answered with an explanation of the two categories that exist in the network topology.
- Physical – The physical network topology refers to the actual connections (wires, cables, etc.) of how the network is arranged. Clearly, setup, maintenance, and provisioning tasks require insight into the physical network.
- Logical – The logical network topology is a higher-level idea of how the network is set up, including which nodes connect to each other and in which ways, as well as how data is transmitted through the network. Logical network topology includes any virtual and cloud resources.
Effective network management and monitoring require a strong grasp of both the physical and logical topology of a network to ensure your network is efficient and healthy.
What’s the Most Common Type of Network Topology?
Building a local area network (LAN) topology can be make-or-break for your business, as you want to set up a resilient, secure, and easy-to-maintain topology. There are several different types of network topology and all are suitable for different purposes, depending on the overall network size and your objectives.
The main types of network topology are:
What is Bus Topology?
Bus topology is where all the nodes in the network are arranged in a line with the connection running directly between devices.
Pros of Bus Topology
This topology transmits data in only one direction and is a cost-effective and easy network type to set up.
Cons of Bus Topology
If one point along the cable fails, the entire network goes down. Additionally, with large network traffic or lots of nodes, the whole network performance becomes slower.
What is Ring Topology?
Ring topology is where nodes are arranged in a circle (or ring). The data can travel through the ring network in either one direction or both directions, with each device having exactly two neighbors.
Pros of Ring Topology
This type of network topology can sustain larger networks more easily without too much complexity.
Cons of Ring Topology
Like bus topology, if one point along the chain goes down in a ring topology setup, the whole network is affected. Ring topology can also be slower than other network topology types since data must also travel across each device in the network.
What is Star Topology?
In star network topology, there is one central node, and all other nodes are connected to this node with an individual connection. The central node is a server, and the other nodes are clients. Each client is only indirectly connected to the others, and the central node manages all the data transmissions throughout the network.
Pros of Star Topology
The primary advantage of star topology is you can manage every device on the network through this one central device, and if one of the clients goes down, the network will remain up. This creates a layer of protection and makes the network more robust. You can also easily add more nodes or clients in a star network, and they’re relatively easy to troubleshoot.
Cons of Star Topology
The main risk in star topology is if the central node (the server) goes down, the entire network will go down. The network administrator will need to manage the health of the server very carefully to protect the rest of the network in a star topology setup.
What is Tree Topology?
A tree topology is a kind of extension of bus and star topologies. The main node, called a root node, is connected to the other parts of the network in a parent-child pattern. To be called a tree topology, these parent-child connections must span three levels of hierarchy.
Pros of Tree Topology
This kind of topology makes it easy to add more nodes to as your network grows, as you can simply add more nodes in the hierarchy. It’s also relatively easy to troubleshoot since you can systematically check through the tree structure.
Cons of Tree Topology
Like a star network, the risk in a tree topology is the root node and parent nodes; if a parent node goes down, that entire branch of the tree will go down. Tree topology also requires more wiring than other network types, which can push costs up.
What is Mesh Topology?
Mesh topology is much more complex, as most nodes in the network are connected to the others. Mesh topology also has two different types:
- In a partial mesh topology, most are connected, but some nodes are left separate from the others.
- In a full mesh topology, every node is connected to the others.
In mesh topology, data is transmitted through either flooding or routing. Flooding is where data is sent to all the nodes in the network without logic, while routing is where data is sent more specifically through the network using the shortest route.
Pros of Mesh Topology
Mesh network topologies are generally used because they’re very resistant to failure due to a large number of connections between the nodes. If one node goes down, the data can take a number of other routes.
Cons of Mesh Topology
Mesh topologies are more difficult to set up and configure, due to the complexity of this network topology type. You’ll also need a large amount of wiring for this type of network topology setup, which can be expensive.
What is Hybrid Topology?
Hybrid topologies are self-explanatory: they’re a combination of multiple topologies in one network. This usually occurs when multiple parts of a company or enterprise network use different topologies that end up connected through a central server. Hybrid topology can also apply to networks connected to cloud platforms or virtual resources, which complicates the logical network topology.
Pros of Hybrid Topology
Due to the variation in topologies, these kinds of networks are usually very flexible and resilient.
Cons of Hybrid Topology
Hybrid topology can be complex to manage and troubleshoot.
What Tools Help Manage and Monitor Networks?
Due to variations in network topology and the different ways networks can behave—including their unique security issues, pressure points, and management challenges—it’s often useful to automate configuration and management tasks using network software.
First, consider using a network configuration management tool. This kind of tool can help you configure your network correctly and automate repetitive tasks to take the pressure off the network administrator. As your organization or network grows, the network topology may become more layered or more complex, and it can become harder to deploy configurations across the entire network with certainty. However, with configuration management tools, the complicated network topology is no issue: tools can usually auto-detect each node on the network, allowing you to deploy standard configurations that may be required for compliance reasons, or flag any configurations outside what is expected.
Network configuration management tools can also highlight vulnerabilities, so you can correct these issues and keep your network more secure. Finally, these kinds of tools should also display the lifecycle of the devices on your network, alerting you to devices coming to their end-of-service or end-of-life points, so you can replace them before problems begin to arise.
Network Performance Troubleshooting
The next kind of tool you should use is network management software to track overall performance. A performance manager can keep track of network issues, outages, and performance issues. A performance management tool will also have the functionality to set network performance baselines and establish a clear picture of how your network typically behaves when healthy. Then, by setting alerts when your network performs unexpectedly or outside of these baselines, you can quickly track, pinpoint, and troubleshoot issues.
With complex network topologies, it may be hard to figure out exactly which part of the network is having issues. Some performance managers will create a visual display of your network topology, so you can see the entire network in a one-map overview. This can show you how your network is laid out, bring your attention to changes in the topology, and flag where problems are arising. To get started understanding your network topology, you can try a tool like SolarWinds® Network Topology Mapper free for 14 days. Network Topology Mapper automatically discovers and generates detailed topology maps of your network and can create multiple map types without having to rescan your network every time.
Network Topology in 2019
As networks become increasingly complex, and as large businesses shift towards digitizing everything, understanding the layout of your network and the appropriate tools to manage it becomes increasingly important. By using network management and configuration tools, you can keep track of your network topology and the performance of your network, no matter how it grows or changes.