EC2 实例如何访问 Internet IP 以与 EC2 实例所在的 VPC 相同的 CIDR 前缀开始？

Question

How can EC2 instance access internet IP starting with the same CIDR prefix of the VPC the EC2 instance is in?

Assume you have a VPC with CIDR 123.78.0.0/16 and you have the following entry in the routing table to allow VPC EC2 instances to access each other

• destination:123.78.0.0/16
• target:local How can you access an internet server with IP 123.78.xx (for example 123.78.1.1) from an EC2 instance in this VPC?

Answer 1

You will typically want to use a private IP address range with your VPC to avoid clashing with somebody who owns and operates a public IP address.

Private ranges are:

• 10.0.0.0/8
• 172.16.0.0/12
• 192.168.0.0/16

You can also use subsets of these ranges, such as 10.0.0.0/16 .

The additional benefit of using a private IP range is that Internet traffic cannot route to these IP addresses without going via a NAT Router (such as the one you have at home, which translates a public IP address to a private IP address on your home network).

While it is possible to use Public IP addresses (eg 123.78.0.0/16 ) in a VPC, this should be avoided unless you actually own the range and want to allow routing to it.