etcd cluster issue "error "tls: first record does not look like a TLS handshake"

[soklangsum]

HI guy,
I have follow your document guide just changed IP address to my environment.
when I try to start etcd cluster got error as below:

Apr 07 09:35:10 master1 etcd[4769]: rejected connection from "x.x.x.x:41834" (error "tls: first record does not look like a TLS handshake", ServerName "")
Apr 07 09:35:03 master2 etcd[4758]: rejected connection from "x.x.x.x:37848" (error "tls: first record does not look like a TLS handshake", ServerName "")
Apr 07 09:34:42 master3 etcd[4814]: rejected connection from "x.x.x.x:58962" (error "tls: first record does not look like a TLS handshake", ServerName "")

Thanks,
Soklang