Security group for public ALB when it is a target for private NLB

0

What should be my security group rule when Internet-facing ALB is introduced as a target to private NLB?

This documentation (https://docs.aws.amazon.com/elasticloadbalancing/latest/network/application-load-balancer-target.html) states that the security group should allow traffic from Client's computer. In my case, the client will be APIGW + VPC Link

APIGW -> VPC Link -> Private NLB -> Public ALB

2 回答
1

You should set your ALB's security group inbound rules to accept HTTP/S traffic only from the security group that is associated to the NLB.

This way the ALB will only accept inbound traffic from the NLB regardless the source IP (it will take care to allow both the health checks originated from the NLB network interfaces IP and the traffic originated by the clients that the NLB preserves.

AWS
已回答 2 个月前
profile pictureAWS
专家
已审核 2 个月前
0

This article should help: https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-update-security-groups.html.

I would do as follows:

Security group for public ALB: Inbound :NLB client IP, 443, VPC Cidr of the NLB Outbound: instances behind ALB

profile picture
专家
已回答 2 个月前
profile picture
专家
已审核 2 个月前
  • Doesn't the NLB preserve the source IP?

  • It does but I think it depends on how you then register the target: https://repost.aws/knowledge-center/elb-capture-client-ip-addresses.

    For Network Load Balancers, register your targets by instance ID to capture client IP addresses without additional web server configuration. For instructions, see Target group attributes instead of the following resolutions.

    For Network Load Balancers when you can register only IP addresses as targets, activate proxy protocol version 2 on the load balancer. For instructions, see Enable proxy protocol instead of the following resolutions.

您未登录。 登录 发布回答。

一个好的回答可以清楚地解答问题和提供建设性反馈,并能促进提问者的职业发展。

回答问题的准则