The network administrator is asked to configure 113 point-to-point links. Which IP addressing scheme best defines the address range and subnet mask that meet the requirement and waste the fewest subnet and host addresses?
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A. B. C. D. E.D
To configure 113 point-to-point links, we need to choose an IP addressing scheme that defines an address range and subnet mask with the fewest wasted subnet and host addresses.
We need to choose the subnet mask that will allow us to have the required number of point-to-point links without wasting any IP addresses. To achieve this, we need to select a subnet mask that provides four usable IP addresses per subnet (two usable addresses are required for each point-to-point link - one for each end).
Let's examine each answer choice:
A. 10.10.0.0/18 subnetted with mask 255.255.255.252 This option provides 4,096 subnets and 4 hosts per subnet, resulting in 4,092 wasted IP addresses per subnet. This is not an optimal choice since it wastes too many addresses.
B. 10.10.0.0/25 subnetted with mask 255.255.255.252 This option provides 128 subnets and 4 hosts per subnet, resulting in 2 wasted IP addresses per subnet. We need 113 subnets, so we need to use at least 7 bits for subnetting, which gives us 128 subnets. Therefore, this is a valid option, but we will have some unused IP addresses in each subnet.
C. 10.10.0.0/24 subnetted with mask 255.255.255.252 This option provides 256 subnets and 4 hosts per subnet, resulting in 2 wasted IP addresses per subnet. However, we need only 113 subnets, so we would have a lot of wasted IP addresses.
D. 10.10.0.0/23 subnetted with mask 255.255.255.252 This option provides 512 subnets and 4 hosts per subnet, resulting in 2 wasted IP addresses per subnet. We only need 113 subnets, so this option would waste a lot of IP addresses.
E. 10.10.0.0/16 subnetted with mask 255.255.255.252 This option provides 65,536 subnets and 4 hosts per subnet, resulting in 2 wasted IP addresses per subnet. However, we only need 113 subnets, so this option would waste a significant amount of IP addresses.
Therefore, the best choice is option B, which provides the required number of subnets with the least number of wasted IP addresses per subnet.