即如果您的ELB在VPC A 与10.0.0.0/8，并且您有另一个VPC B 与10.0.0.0/8那里's no way it could differentiate that route. It would be dangerous to cross that boundary and send data say to 10.0.0.8 if there was an instance in both VPC'与该IP . 它没有可以解决这个问题的路线 . 如果要将数据从VPC发送到VPC，则'd need a VPC peering connection and routes that handle that. Then you' d发送到VPC A 中的代理，该代理将其发送到ELB或VPC中的实例 B
2 回答
AWS现在提供Application Load Balancing via IP Addresses . 这意味着您可以配置ALB以直接将流量路由到任何对等VPC中的IP . 这可以保护您免受额外的跳跃和更大的复杂性，另外一个自定义代理层将带来它 .
ELB只能附加可通过它访问的实例 .
当您将ELB放置在VPC中时，它会受到约束 . VPC是独立的，可以有重叠的子网范围 .
即如果您的ELB在VPC
A与10.0.0.0/8，并且您有另一个VPCB与10.0.0.0/8那里's no way it could differentiate that route. It would be dangerous to cross that boundary and send data say to 10.0.0.8 if there was an instance in both VPC'与该IP . 它没有可以解决这个问题的路线 . 如果要将数据从VPC发送到VPC，则'd need a VPC peering connection and routes that handle that. Then you' d发送到VPCA中的代理，该代理将其发送到ELB或VPC中的实例B