On an Amazon Web Services (AWS) infrastructure, some subnet addresses are reserved for items specific to the platform. CDV will store IP addresses reserved in subnets by AWS as IP addresses with corresponding types in a BlueCat Address Manager (BAM) network. Reserved IP addresses are supported only for private virtual networks and subnets.
CDV supports the import of both IPv4 and IPv6 reserved IP addresses. When discovering reserved IP addresses, if a specific reserved address is already used in Address Manager, CDV will log an error in the CDV error log file.
Within a subnet, AWS reserves the first four IP addresses and the last IP address, for a total of five IP addresses within each subnet CIDR block. CDV will map the reserved IP addresses to IP addresses on BAM as follows:
IPv4 networks
| Unusable address | AWS | BAM | Example |
|---|---|---|---|
| First address | Network address | Network ID | 10.1.1.0 from CIDR range 10.1.1.0/24 |
| Second address | Reserved by AWS for the VPC router | Gateway address | 10.1.1.1 from CIDR range 10.1.1.0/24 |
| Third address | Reserved by AWS | Reserved address | 10.1.1.2 from CIDR range 10.1.1.0/24 |
| Fourth address | Reserved by AWS for future use | Reserved address | 10.1.1.3 from CIDR range 10.1.1.0/24 |
| Last address | Network broadcast address | Broadcast address | 10.1.1.255 from CIDR range 10.1.1.0/24 |
IPv6 networks
| Unusable address | AWS | BAM | Example |
|---|---|---|---|
| First address | Network address | Network ID | 2a05:d012:f61:3600:: from CIDR range 2a05:d012:f61:3600::/64 |
| Second address | Reserved by AWS for the VPC router | Static address |
2a05:d012:f61:3600::1 from CIDR range 2a05:d012:f61:3600::/64 |
| Third address | Reserved by AWS | Static address |
2a05:d012:f61:3600::2 from CIDR range 2a05:d012:f61:3600::/64 |
| Fourth address | Reserved by AWS | Static address | 2a05:d012:f61:3600::3 from CIDR range 2a05:d012:f61:3600::/64 |
| Last address | Reserved by AWS | Static address | 2a05:d012:f61:3600:ffff:ffff:ffff:ffff from CIDR range 2a05:d012:f61:3600::/64 |