This is the correct command list that will satisfy the requirements with the least number of commands. Option C contains four commands that will create VLAN 25, assign it to VRF eng, create an SVI for VLAN 25 with IPv4 and IPv6 addresses, and enable the SVI. The other options are incorrect because they either contain more commands than necessary or do not meet all the requirements.

Active Gateway is the first-hop protocol feature that is used for VSX L3 gateway as per Aruba recommendation. Active Gateway is a feature that allows both VSX peers to act as active gateways for different subnets, eliminating the need for VRRP or other first-hop redundancy protocols. Active Gateway also provides fast failover and load balancing for L3 traffic across the VSX peers. The other options are incorrect because they are either not recommended or not supported by Aruba CX VSX.

The difference in the noise floor perceived by a client using a bonded 40 MHz wide channel as compared to an unbonded 20 MHz wide channel is 3 dB. The noise floor is the level of background noise in a given frequency band. When two adjacent channels are bonded, the noise floor increases by 3 dB because the bandwidth is doubled and more noise is captured. The other options are incorrect because they do not reflect the correct relationship between bandwidth and noise floor.

802.3bz is a standard for Ethernet over twisted pair at speeds of 2.5 and 5 Gbit/s. These use the same cabling as the ubiquitous Gigabit Ethernet, yet offer higher speeds. The resulting standards are named 2.5GBASE-T and 5GBASE-T.

To establish a keepalive connection between two Aruba CX 8325 switches for VSX configuration, you need to use a routed port in custom VRF. A routed port is a physical port that acts as a layer
3 interface and does not belong to any VLAN. A custom VRF is a virtual routing and forwarding instance that provides logical separation of routing tables. By using a routed port in custom VRF, you can isolate the keepalive traffic from other traffic and prevent routing loops or conflicts. The other options are incorrect because they either do not use a routed port or do not use a custom VRF.