By using AWS re:Post, you agree to the AWS re:Post Terms of Use
AWS re:Postre:Post

NLB lost one of assigned IP adresses.

0

Hello community.

I have a Network Load Balancer in my infrastructure. It was deployed to the two private subnets in two availability zones. It was working well until I noted that one of the assigned internal IP addresses for inbound connections was lost. I verified that by host and dig commands.
I found a lost IP on my Network interfaces. I can see that it is still assigned to the correct subnet and has the right interface type network_load_balancer.

My question: How can I return my IP address, or maybe network interface, to my NLB? Do you have any ideas?

Tags
Network Load Balancer
Language
English
Stanislav
asked 2 months ago67 views
1 Answer
2
Accepted Answer

Is the DNS name that you are looking at with dig configured as an "alias" record in a Route 53 hosted zone? They allow an "evaluate target health" option to be enabled, which automatically removes the IPs from DNS that aren't reporting as healthy.

Particularly if your NLB or the target group is configured not to allow cross-AZ load balancing, the NLB might not have any functioning targets in a given AZ, causing its IP to be removed from DNS. The cross-AZ load balancing option is described in these documentation articles:

EXPERT
Leo K
answered 2 months ago
profile picture
EXPERT
Oleksii Bebych
reviewed 2 months ago
  • Stanislav
    2 months ago

    Hello Leo

    Thank you for your answer. This is exactly what happened to us. Two ECS (faragate) services started in one AZ, and we didn't have cross-zone balancing enabled at our NLB. This is caused by NLB disabling or making inactive one of the IPs.

    This is what the AWS support told us.

    Thank you, Stanislav

You are not logged in. Log in to post an answer.

A good answer clearly answers the question and provides constructive feedback and encourages professional growth in the question asker.

Guidelines for Answering Questions

Relevant content