Dual-core switch configuration example

A dual-core switch setup typically involves configuring two core switches in a redundant topology using VSX, MLAG, or SmartLink, with inter-switch links and VLANs for high availability and traffic aggregation. Key ConceptsDual-core switch topologies are designed to provide redundancy and high availability in enterprise or data center networks. Common approaches include: VSX (Virtual Switching Extension): Used in Aruba CX switches to create a logical pair of core switches that share Layer 2 and Layer 3 responsibilities, allowing multi-chassis link aggregation (MC-LAG) to access switches.

MLA

G (Multi-Chassis Link Aggregation): Provides similar functionality but may not be supported on all hardware.

Smart

Link: A simpler redundancy mechanism for VLAN failover when MLAG is not available. Example Configuration Steps (Aruba VSX)Create Inter-Switch Link (ISL): Define a Link Aggregation Group (LAG) on both core switches to serve as the VSX data plane inter-switch link.

Assign the LA

G to the VSX configuration.

Configure VLA

Ns: Create VLANs for traffic routing to upstream networks. Use the same VLAN for the routed transit path between the cores to ensure failover if one core loses external connectivity.

Enable VS

X: Use the Aruba Central UI or MultiEdit tool to enable VSX on both cores.

Assign the LA

G as the VSX ISL. Configure out-of-band management interfaces for VSX keepalives to maximize port availability for access switches. Connect Access Layer: Configure MC-LAG or standard LAGs from access switches to both cores.

Ensure VLA

Ns are propagated correctly across the VSX pair. Example Configuration Steps (SmartLink Across Dual-Core Mesh)Topology: Two core switches in a mesh topology. Access layer switches form a VSF stack connecting to both cores.

Smart

Link Setup: Assign VLANs (e.g., 10, 20, 30) to SmartLink. Optionally, create a dedicated VLAN for SmartLink control to manage failover traffic. Failover Behavior: If one core fails, SmartLink automatically redirects traffic to the other core.

No MLA

G is required, but redundancy is maintained at the VLAN level.

Cisco Dual-

Core Example

Connect devices to both core switches. Configure zoning and interop mode if using heterogeneous SAN switches (e.g., MDS 9000 with McData 6064). Ensure both cores propagate configuration changes and provide full security for attached devices.

Use Layer 3 10 GigE links for redundancy and high throughput between cores and aggregation modules.

Best Practices

Always configure redundant links between cores and aggregation layers. Use dedicated VLANs for control traffic (VSX keepalives or SmartLink). Test failover scenarios to ensure traffic continuity.

Document LA

Gs, VLANs, and inter-switch links for troubleshooting. This configuration ensures high availability, load balancing, and seamless failover in a dual-core switch environment, whether using Aruba VSX, Cisco dual-core, or SmartLink mechanisms.