Wiring the two aggregation switches

The recommended wiring method for two aggregation switches is to use Link Aggregation (LAG) or stacking, depending on switch capabilities, to combine multiple physical links into a single logical connection for increased bandwidth and redundancy. Link Aggregation (LAG)Link Aggregation combines multiple physical ports between two switches into a single logical link, providing higher throughput and failover protection. Key points include: Protocol Support: Ensure both switches support the same aggregation standard, typically IEEE 802.

3ad (LACP) for dynamic aggregation or static LAG for manual configuration. Port Selection: Use multiple ports of the same speed and duplex. Avoid applying authentication or VLAN restrictions to these ports.

Configuration Steps: On Switch A, create a LAG group and select the ports to include.

Set the LA

G type (LACP or static) and load balancing mode (commonly MAC address-based). Repeat the same configuration on Switch B, ensuring identical settings. Connect the selected ports with Ethernet cables, ideally routed over separate physical paths to reduce simultaneous failure risk.

Benefits: Aggregated links provide combined bandwidth, redundancy, and load balancing. If one link fails, traffic continues over remaining links with minimal disruption.

Stacking

If the switches support stacking, this method can provide a single logical switch with a shared backplane: Connection: Use dedicated stacking ports and specialized stacking cables to daisy-chain the switches. Advantages: Stacking offers higher bandwidth than individual links, unified management, and redundancy across the stack. Limitations: Stacking generally requires switches from the same manufacturer and model family.

Cascading

For switches without stacking support, cascading is an alternative: Method: Connect two switches using one or more Ethernet ports. Multiple cables can be used for redundancy, but each link is managed independently unless aggregated. Use Case: Useful for expanding port count while maintaining independent switch management.

Best Practices

Redundancy: Run aggregated cables over different physical paths to prevent simultaneous failure.

VLA

N Configuration: Ensure LAG ports are not assigned to specific VLANs individually; configure VLANs on the aggregated link instead. Monitoring: Verify LAG status on both switches to ensure all member ports are active and functioning correctly. Layer 2 vs Layer 3: Aggregation switches can operate at Layer 2 or Layer 3.

Configure routing, VLANIF interfaces, and DHCP as needed for your network topology. By following these methods, two aggregation switches can be connected to maximize bandwidth, reliability, and network efficiency while maintaining proper management and failover capabilities.