Network Topologies Cheatsheet

Network topologies describe the physical or logical arrangement of network devices.

1. Star Topology

  • Description: All nodes are connected to a central device (switch, hub, or router).
  • Advantages:
    • Easy to set up and manage.
    • Fault isolation (failure of one node doesn’t affect others).
    • Scalable by adding new devices to the central hub.
  • Disadvantages:
    • Single point of failure (central device).
    • Requires more cabling than bus topology.
  • Use Cases:
    • Home networks.
    • Small to medium-sized office networks.

2. Bus Topology

  • Description: All nodes are connected to a single backbone cable.
  • Advantages:
    • Easy and inexpensive to set up.
    • Requires minimal cabling.
  • Disadvantages:
    • Backbone failure affects the entire network.
    • Difficult to troubleshoot.
    • Performance degrades with more devices.
  • Use Cases:
    • Legacy LAN setups.
    • Small networks with limited devices.

3. Ring Topology

  • Description: Nodes are connected in a circular fashion, with data traveling in one direction (unidirectional) or both directions (bidirectional).
  • Advantages:
    • Predictable data transmission (deterministic).
    • Easier troubleshooting compared to bus topology.
  • Disadvantages:
    • Failure in one node can disrupt the entire network (unless dual-ring).
    • Difficult to reconfigure or scale.
  • Use Cases:
    • Fiber Distributed Data Interface (FDDI).
    • Token Ring networks (now obsolete).

4. Mesh Topology

  • Description: Each node connects to every other node, creating multiple redundant paths.
  • Advantages:
    • Highly reliable (no single point of failure).
    • Load balancing possible.
  • Disadvantages:
    • Expensive to implement.
    • Complex to manage and maintain.
  • Use Cases:
    • High-performance and fault-tolerant networks (e.g., WANs, military systems).

5. Tree (Hierarchical) Topology

  • Description: A combination of star and bus topologies, with a root node and hierarchical branching.
  • Advantages:
    • Scalable (allows hierarchical grouping).
    • Fault isolation within branches.
  • Disadvantages:
    • Backbone failure disrupts the entire tree.
    • Higher cabling costs compared to star topology.
  • Use Cases:
    • Enterprise networks.
    • Large-scale LANs.

6. Hybrid Topology

  • Description: Combination of two or more topologies (e.g., star-ring, star-bus).
  • Advantages:
    • Flexible and scalable.
    • Can optimize topology for specific needs.
  • Disadvantages:
    • Complex to design and manage.
    • Higher cost due to mixed technologies.
  • Use Cases:
    • Data centers.
    • Modern corporate networks.

Topology Summary Table

TopologyAdvantagesDisadvantagesUse Cases
StarEasy to manage, fault isolationCentral device failure affects networkHome and office networks
BusSimple, cost-effectiveBackbone failure disrupts all devicesSmall/legacy LANs
RingPredictable, efficient data flowNode failure affects networkFDDI, Token Ring
MeshHighly reliable, fault-tolerantExpensive, complexWANs, high-reliability networks
TreeScalable, hierarchical organizationBackbone failure affects networkEnterprise LANs
HybridFlexible, scalableExpensive, complexData centers, corporate networks

Visualization of Topologies

Star Topology

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[Node]   [Node]
    \     /
    [Switch]
    /    \ 
[Node]   [Node]

Bus Topology

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[Node] – [Node] – [Node] – [Node]

Ring Topology

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+-----+
|     |
|     |---------
|     |        |
+-----+        |
   |           |
   |           |
+-----+     +-----+
|     |     |     |
|     |-----|     |
|     |     |     |
+-----+     +-----+

Tree Topology

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           .              
           |           
        .--+--.       
       |       |    
      .+.     .+.    
     |   |   |   |     
     1   2   3   4

Hybrid Topology combines any elements of the 5 topologies listed above.