Chapter 4: Amazon Virtual Private Cloud
- 1. A. The allowed range of prefix lengths for a VPC CIDR is between /16 and /28 inclusive. The maximum possible prefix length for an IP subnet is /32, so /56 is not a valid length.
- 2. C. A secondary CIDR may come from the same RFC 1918 address range as the primary, but it may not overlap with the primary CIDR. 192.168.0.0/24 comes from the same address range (192.168.0.0–192.168.255.255) as the primary and does not overlap with 192.168.16.0/24. 192.168.0.0/16 and 192.168.16.0/23 both overlap with 192.168.16.0/24. 172.31.0.0/16 is not in the same range as the primary CIDR.
- 3. A, D. 10.0.0.0/24 and 10.0.0.0/23 are within the VPC CIDR and leave room for a second subnet. 10.0.0.0/8 is wrong because prefix lengths less than /16 aren’t allowed. 10.0.0.0/16 doesn’t leave room for another subnet.
- 4. B. Multiple subnets may exist in a single availability zone. A subnet cannot span availability zones.
- 5. A. Every ENI must have a primary...
