Amazon Virtual Private Cloud (VPC) | Routing and Topology

Question 1

Can I assign one or more Elastic IP (EIP) addresses to VPC-based Amazon EC2 instances?

Routing and Topology

Amazon Virtual Private Cloud (VPC) | Networking & Content Delivery

Answer 1

Yes, however, the EIP addresses will only be reachable from the Internet (not over the VPN connection). Each EIP address must be associated with a unique private IP address on the instance. EIP addresses should only be used on instances in subnets configured to route their traffic directly to the Internet gateway. EIPs cannot be used on instances in subnets configured to use a NAT gateway or a NAT instance to access the Internet. This is applicable only for IPv4. Amazon VPCs do not support EIPs for IPv6 at this time.

Question 2

What does an Amazon VPC router do?

Routing and Topology

Amazon Virtual Private Cloud (VPC) | Networking & Content Delivery

Answer 2

An Amazon VPC router enables Amazon EC2 instances within subnets to communicate with Amazon EC2 instances in other subnets within the same VPC. The VPC router also enables subnets, Internet gateways, and virtual private gateways to communicate with each other. Network usage data is not available from the router; however, you can obtain network usage statistics from your instances using Amazon CloudWatch.

Question 3

Can I modify the VPC route tables?

Routing and Topology

Amazon Virtual Private Cloud (VPC) | Networking & Content Delivery

Answer 3

Yes. You can create route rules to specify which subnets are routed to the Internet gateway, the virtual private gateway, or other instances.

Question 4

Can I specify which subnet will use which gateway as its default?

Routing and Topology

Amazon Virtual Private Cloud (VPC) | Networking & Content Delivery

Answer 4

Yes. You may create a default route for each subnet. The default route can direct traffic to egress the VPC via the Internet gateway, the virtual private gateway, or the NAT gateway.