To adjust virtualization on a core switch, you typically configure features like StackWise Virtual, VLAN virtualization, and Layer 3 interface settings to enable a single logical switch from multiple physical devices.

Enable StackWise Virtual

For Cisco Catalyst switches, StackWise Virtual allows two physical switches to operate as a single logical switch, sharing a control and management plane. To configure it:

• Connect the two switches using the recommended Ethernet links.
• Enable StackWise Virtual on both switches.
• Ensure that MAC addresses for SVIs or routed ports are consistent across the switches, particularly the first four most significant bytes (4MSB) if Layer 3 injected packets are used.
• Avoid enabling FIPS 140-2 simultaneously, as it is mutually exclusive with Secure StackWise Virtual.
• Only 128-bit authorization keys are supported, and DAD links are not compatible with StackWise Virtual .

Configure VLANs and VPN Instances

• Create interconnection VLANs on the core switch and assign interfaces to these VLANs.
• Bind VLANIF interfaces to VPN instances to isolate traffic between public networks and firewall return paths.
• Configure OSPF or other routing protocols to ensure proper connectivity between user networks and egress networks .

Layer 3 and Redundancy Considerations

• Fine-tune First Hop Redundancy Protocol (FHRP) and PIM timers for rapid fault detection and recovery.
• Align FHRP priorities with STP root priorities to prevent loops and ensure consistent Layer 2 and Layer 3 operation.
• Ensure that all SVIs or routed ports that require Layer 3 injected packets follow the MAC address consistency rules .

CPU Virtualization (Optional)

If the core switch supports virtualized network functions or hypervisor-based services, you may need to enable CPU virtualization in the BIOS/UEFI:

• For Intel CPUs, enable VT-x; for AMD CPUs, enable SVM Mode.
• This allows the switch or associated virtual machines to efficiently utilize CPU resources for virtualized workloads .

Summary

Adjusting virtualization on a core switch involves:

1. Enabling StackWise Virtual for logical switch operation.
2. Configuring VLANs, VLANIF interfaces, and VPN instances for traffic isolation.
3. Fine-tuning Layer 3 protocols and redundancy mechanisms.
4. Optionally enabling CPU virtualization if running virtualized network functions. Following these steps ensures optimized performance, high availability, and proper traffic segmentation on a virtualized core switch.