In a typical local area network (LAN) configuration, a gateway usually takes the form of a set of line ware or switches and a number of computers. However, as the size of the network continues to grow, the number of computers increases, and the need for higher performance increases, enterprise IT environments are gradually adopting more advanced technologies. In such an evolution, switches gradually replaced hubs, and interconnections between multiple switches gradually replaced a single switch layout.
In large switch environments with multiple switches, the following three approaches address critical key technologies: cascading, stacking, and clustering.
Cascading technology allows multiple switches to be interconnected, enabling more complex network topologies. Stacking is the consolidation of multiple switches into a single unit through dedicated stacking ports, providing greater port density and superior performance. Clustering manages multiple interconnected switches as a single logical device, reducing the performance cost of network management and the complexity of management operations.
| Notion | Advantage | Disadvantage | Applicable Scenarios |
Cascading | Two or more switches are connected by forming a bus-type, tree-type, or star-type cascade structure.
LANs are generally divided into three layers: the core layer, the aggregation layer, and the access layer. | Lower cost.
Easier to manage | There is a limit to the number of layers that can be cascaded between switches.
Multiple switches must support the Spanning Tree Protocol.
The speed of the lower layer switch is limited to the speed of the Layer 3 switch. | Small networks: small business or departmental offices |
Stacking | Multiple switches are connected through dedicated stacking ports to form a logical single device. | Single management domain simplifies configuration and monitoring.
High bandwidth to improve internal network transmission speed. | The number of switches is limited.
Requirement of close equipment location. | Small or medium size enterprise (SME) |
Clustering | Management of other switches by one command switch virtualizes multiple switches as logical devices for management. | Multiple switches share configuration and control panels, but each member switch still maintains an independent data plane.
Flexibility. | There are limitations that are implemented differently by different manufacturers. | Large-scale network |
1. Switch Cascading
Definition: A switch cascade is the connection of multiple switches over physical links to form an extended network. Data is passed over the links between the switches, each with its own individual configuration.
Connection: Connects a port on one switch to a port on another switch using a common physical link (usually an Ethernet link).
Advantages:
Cost-effectiveness: Cascading is a relatively low-cost approach because it does not involve specialized stacking or clustering techniques.
Simplicity: Deployment and maintenance are relatively simple and do not require specialized hardware or protocols.
Applicable Scenarios:
Small Networks: For smaller networks, such as small office or departmental level networks.
2. Switch Stacking
Definition: Switch stacking is the process of connecting multiple physical switches together through special stacking ports to form a logical unit. These physical switches are logically treated as a single switch.
Connection: Multiple physical switches are connected together through stacking modules or ports, usually using a specific stacking protocol.
Advantages:
Single Management Domain: All stacked switches are treated as a single management unit, simplifying configuration and monitoring.
High Bandwidth: Stacked ports typically provide high-bandwidth connections, increasing the speed of data transfer between internal switches.
Applicable Scenarios:
SMB: For small and medium-sized business networks that require bandwidth and management efficiency.
Core Layer: Stacking is typically deployed at the core layer of a network to provide high bandwidth and redundancy.
3. Switch Clustering
Definition: Switch clustering is the process of connecting multiple switches together to form a logical unit that shares the same configuration and control plane. Each member switch still retains a separate data plane.
Connection: A special cluster connection is used to pass configuration information over a dedicated control link.
Advantages:
Shared Control Plane: All members of the cluster share the same configuration information, improving consistency.
Flexibility: Allows switches to be added or removed from the cluster, improving system scalability.
Applicable Scenarios:
Large Enterprises: For large enterprise networks that require flexibility and scalability.
Redundancy Requirements: Provides redundancy by allowing the cluster to continue to operate if a switch fails.
In summary, when choosing an architecture for switches, tradeoffs need to be made based on network size, performance needs, and manageability. Cascading is suitable for small networks, stacking is suitable for small and medium-sized enterprises, and clustering is suitable for large enterprise networks. Each architecture has its advantages and applicable scenarios, and administrators should choose based on actual needs to build a high-performance, high-availability enterprise network.
