Amazon Virtual Private Cloud

Amazon Virtual Private Cloud (VPC) is a commercial cloud computing service that provides users a virtual private cloud, by "provision[ing] a logically isolated section of Amazon Web Services (AWS) Cloud".^[1] Enterprise customers are able to access the Amazon Elastic Compute Cloud (EC2) over an IPsec based virtual private network.^[2][3] Unlike traditional EC2 instances which are allocated internal and external IP numbers by Amazon, the customer can assign IP numbers of their choosing from one or more subnets.^[4] By giving the user the option of selecting which AWS resources are public facing and which are not, VPC provides much more granular control over security. For Amazon it is "an endorsement of the hybrid approach, but it's also meant to combat the growing interest in private clouds".^[5]

IP Addressing

Initially, users are able to choose a range of IP addresses for their VPC. Within this range, users can assign various private and public IP addresses to instances in the VPC in order to communicate with the Internet and other instances of VPC's. These addresses are assigned to specific instances rather than the user's entire VPC account.^[6] Assignment of Public IP addresses is not possible, instead the address is assigned and unassigned in certain cases, causing the address of an instance to change. When a consistent IP address is needed, a third type of IP Address, Elastic IP addresses, can be used in place of Public IP addresses.^[6]

Connectivity

AWS VPC allows users to connect to the Internet, a user's corporate data center, and other users' VPCs.^[7]

Connecting to the Internet

Users are able to connect to the Internet by adding an Internet Gateway to their VPC, which assigns the VPC a public IP Address.^[8]

Connecting to a Data Center

Users are able to connect to a data center by setting up a Hardware Virtual Private Network connection between the data center and the VPC. This connection allows the user to "interact with Amazon EC2 instances within a VPC as if they were within [the user's] existing network."^[7]

Peering

Users are able to route traffic from one VPC to another VPC using private IP addresses, and are able to communicate as if they were on the same network. Peering can be achieved by connecting a route between two VPC's on the same account or two VPC's on different accounts in the same region. VPC Peering is a one to one connection, but users are able to connect to more than one VPC at a time.^[9]

Privacy

AWS VPC's security is two-fold: firstly, AWS VPC uses security groups as a firewall to control traffic at the instance level, while it also uses network access control lists as a firewall to control traffic at the subnet level.^[10] As another measure of privacy, AWS VPC provides users with the ability to create "dedicated instances" on hardware, physically isolating the dedicated instances from non-dedicated instances and instances owned by other accounts.^[11]

Pricing

AWS VPC is free, with users only paying for the consumption of EC2 resources. However, if choosing to access VPC via a Virtual Private Network (VPN), there is a charge. As with standard EC2 instances, users are able to purchase Reserved Instances, however VPC EC2 Reserved Instance discounts will not be applied to standard EC2 instances, as opposed to standard EC2 Reserved Instances which do apply to VPC instances.^[12]

VPN Connection Pricing

• $0.05 per VPN Connection-hour
• $0.048 per VPN Connection-hour for connections to the Tokyo region

VPC Peer Connections Pricing

• $0.01 per GB of data transferred^[13]

Limits

The following is a list of the initial limitations of AWS VPC, and upon request many of the limitations can be extended.

^[14]

See also

• Amazon Elastic Compute Cloud

References

External links

• Seamlessly Extending the Data Center - Introducing Amazon Virtual Private Cloud - blog post by Amazon CTO Werner Vogels