Does AWS Network Load Balancer (NLB) support ALPN?

Question

I'm running a grpc server behind an AWS NLB. The NLB terminates SSL and the connection works from a go client. However a java/scala client connects with ALPN agent (at the moment I'm using conscrypt after failing with jetty), and it seems like at the end of the handshake the nlb does not return h2 as supported protocol which fails the negotiation. Is it just not supported in which case what is the alternative for akka grpc in java/scala with SSL? if it is supported what could the issue?

I'll post some code if it's the latter.

Thanks.

Answer 1

NLB does not support ALPN. See discussion of workaround/hack in: https://github.com/grpc/grpc-java/issues/5543 .

Answer 2

Just launched - Network Load Balancer now supports TLS ALPN Policies https://aws.amazon.com/about-aws/whats-new/2020/05/network-load-balancer-now-supports-tls-alpn-policies/