This is an Aruba-recommended best practice for hardening that only applies to Aruba CX 6300 series switches with dedicated management ports. A dedicated management port is a physical port that is used exclusively for out-of-band management access to the switch. A dedicated management VRF is a virtual routing and forwarding instance that isolates the management traffic from other traffic on the switch. By creating a dedicated management VRF and assigning the management port to it, the administrator can enhance the security and performance of the management access to the switch. The other options are incorrect because they either do not apply to switches with dedicated management ports or do not follow Aruba-recommended best practices. References:
https://www.arubanetworks.com/assets/ds/DS_AOS-CX.pdfhttps://www.arubanetworks.com/assets/tg/TB_Arub