CIDR (Classless Inter-Domain Routing)

Correct Answer: /27

To determine the smallest CIDR notation that accommodates at least 15 devices, we need to find the number of host bits required. Given: - IP address range: 192.168.0.0/24 - Minimum number of devices: 15 Step 1: Determine the number of host bits needed to accommodate at least 15 devices. Number of host bits = log₂(number of devices + 2) Number of host bits = log₂(15 + 2) = log₂(17) ≈ 4.09 We round up to the nearest whole number, so we need at least 5 host bits. Step 2: Calculate the new subnet mask based on the required host bits. Original subnet mask: /24 (255.255.255.0) New subnet mask: 32 - host bits = 32 - 5 = /27 (255.255.255.224) Step 3: Verify the number of available host addresses in the /27 subnet. Number of available host addresses = 2^(host bits) - 2 Number of available host addresses = 2^5 - 2 = 30 Therefore, the smallest CIDR notation that would fit the requirement of accommodating at least 15 devices is /27 (255.255.255.224). This subnet provides 30 available host addresses, which is sufficient for the given requirement.

Correct Answer: 192.168.1.0/26

The question requires identifying a subnet that can accommodate at least 40 network devices. CIDR notation is a method for assigning IP addresses in a subnet. The /26 after the IP address in '192.168.1.0/26' indicates that the first 26 bits are used for the network portion, leaving the remaining (32-26 = 6) bits for assigning to devices in the subnet. Two to the power of 6 equals 64. So, a '/26' subnet can accommodate 64 addresses. However, in practice, the network address and broadcast address take up 2 addresses, leaving 62 addresses for devices. '192.168.1.0/26' can therefore accommodate 40 devices. The other options, '/27', '/28', and '/29' would provide respectively 30, 14, and 6 usable addresses, which are all less than needed for the 40 devices. This is why '192.168.1.0/26' is the best possible answer.

Correct Answer: /26

In this revised question, the requirement for each subnet to support at least 10 devices is clearly stated. Let's analyze the available options: - /29: This would create two subnets, each with 8 IP addresses (6 usable hosts per subnet), which is not enough to support 10 devices in each subnet. - /30: This would create four subnets, each with 4 IP addresses (2 usable hosts per subnet), which is also not enough to support 10 devices in each subnet. - /31: This is not a valid subnet mask for host addresses, as it would only provide 2 IP addresses per subnet (one for the network and one for the broadcast). - /26: This would create four subnets, each with 64 IP addresses (62 usable hosts per subnet), which is more than enough to support 10 devices in each subnet. Therefore, with the added requirement of supporting at least 10 devices in each subnet, the most suitable CIDR notation is /26.