7.3 Static Link Aggregation Explained
Key Concepts of Static Link Aggregation
Static Link Aggregation, also known as Link Aggregation Control Protocol (LACP) without dynamic negotiation, is a method used to combine multiple physical network links into a single logical link. Key concepts include:
- Link Aggregation Group (LAG): A collection of physical links treated as a single logical link.
- Load Balancing: The distribution of network traffic across multiple links in a LAG.
- Redundancy: The ability to maintain network connectivity in case of a link failure.
- Configuration: The process of setting up and managing LAGs on network devices.
Link Aggregation Group (LAG)
A Link Aggregation Group (LAG) is a collection of physical links that are combined to form a single logical link. This allows for increased bandwidth and improved redundancy. LAGs are configured manually, meaning that all participating devices must be configured to recognize the LAG.
Example: In a network with four Ethernet links between two switches, these links can be combined into a single LAG. This LAG will act as a single, higher-capacity link, capable of handling more traffic than any individual link.
Load Balancing
Load Balancing in the context of LAGs refers to the distribution of network traffic across multiple links within the LAG. This ensures that no single link becomes a bottleneck, maximizing the overall throughput of the network. Load balancing can be based on various criteria, such as source and destination IP addresses, MAC addresses, or ports.
Example: If a LAG consists of two links, traffic can be distributed such that all traffic from a specific server is sent over one link, while traffic from another server is sent over the other link. This ensures that both links are utilized efficiently.
Redundancy
Redundancy in LAGs ensures that network connectivity is maintained even if one or more links fail. By combining multiple physical links into a single logical link, LAGs provide a failover mechanism. If one link fails, traffic is automatically rerouted through the remaining links in the LAG.
Example: In a network with a LAG consisting of three links, if one link fails, the other two links will continue to carry the traffic. This ensures that the network remains operational without any interruption.
Configuration
Configuring LAGs involves setting up the physical links and defining the LAG on the network devices. This includes specifying the links that will be part of the LAG, configuring load balancing, and ensuring that all participating devices are aware of the LAG configuration. Proper configuration is crucial for the effective operation of LAGs.
Example: On a MikroTik router, you would create a LAG by selecting the physical interfaces to be included, setting the load balancing method, and applying the configuration. This ensures that the LAG is operational and ready to handle network traffic.