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amazon-web-servicesamazon-ec2aws-cloudformationaws-nlb

AWS Create Listener from Console - All target groups are greyed out

I have a Network Load Balancer (NLB) running in my VPC. I am trying to create a listener for my NLB from the console. The corresponding EC2 instance (that corresponding to my target group) and its listener require SSL. I am creating a listener to use protocol TLS on port 443. When I attempt to assign my targeting group the listener I am attempting to create, I need to be able to forward traffic to my targeting group. The console provides the mechanism as shown below:

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Under "Forward to..." I can see my targeting group, however all the targeting groups under the pull-down are greyed out. Therefore I cannot select it and complete my listener.

I have tried every type of ALPN Policy, and have even tried HTTP/8080 (just as a sanity check). Regardless of what I do, none of the targeting groups in the Forward TO pull-down can be selected. All the related resources (NLB, EC2 of targeting group and its listener, and the targeting group itself) are running/created, etc.

I have never created an NLB before, so not sure what might ve going on here. I would be grateful for any ideas. Thanks.

Solution

  • ok, I figured it out. This is probably AWS 101, but it was not obvious to me (kind of a AWS novice). The problem for me was that my TG was already associated with a listener. Why was it already associated with a listener? Because I had earlier set up the TG for a different (HTTP) listener and forgot to detach it from that listener. As soon as I did that, the TG was selectable in the above pull-down.

    But it makes perfect sense it hindsight. A targeting group can only be associated with a single listener.