What is the subnet mask used for the IPv4 address configured on the SVI in the example?

What is the subnet mask used for the IPv4 address configured on the SVI in the example?

• A. 255.255.255.0
• B. 255.255.0.0
• C. 255.0.0.0
• D. 255.255.255.255

Answer: (A)

Subnetting defines how many devices can share the same VLAN and what range is considered local to that gateway. The SVI IP acts as the gateway for all hosts in its VLAN, so the subnet mask must line up with the addressing plan. Using 255.255.255.0 creates a /24 network, giving 256 addresses in that subnet (typically 254 usable hosts after subtracting network and broadcast). This is a common, practical size for a VLAN in many campus networks, ensuring devices in the same VLAN can reach the gateway directly. The other masks would change the size of the subnet: a /16 or /8 would broaden the local network beyond what the example intends, wasting addresses and potentially causing routing uncertainty; a /32 (255.255.255.255) defines a single IP, which isn’t suitable for a gateway serving multiple hosts in a VLAN. Therefore, 255.255.255.0 is the best fit for the SVI in this context.

Subnetting defines how many devices can share the same VLAN and what range is considered local to that gateway. The SVI IP acts as the gateway for all hosts in its VLAN, so the subnet mask must line up with the addressing plan. Using 255.255.255.0 creates a /24 network, giving 256 addresses in that subnet (typically 254 usable hosts after subtracting network and broadcast). This is a common, practical size for a VLAN in many campus networks, ensuring devices in the same VLAN can reach the gateway directly.

The other masks would change the size of the subnet: a /16 or /8 would broaden the local network beyond what the example intends, wasting addresses and potentially causing routing uncertainty; a /32 (255.255.255.255) defines a single IP, which isn’t suitable for a gateway serving multiple hosts in a VLAN. Therefore, 255.255.255.0 is the best fit for the SVI in this context.