I have an server process with internal registry (on an Amazon EC2 instance). The server starts correctly and the registry binds itself to port 1099. If I use netstat I can see that it is bound:
tcp6 0 0 :::1099 :::* LISTEN 0 3258 765/java
Additionally I've added Port 1099 TCP to the security group of the instance. If I sstart nmap on the host, it lists the port as open:
Host is up (0.061s latency).
Not shown: 997 filtered ports
PORT STATE SERVICE
22/tcp open ssh
1098/tcp closed unknown
1099/tcp open unknown
However, it is no possible for the client to connect to the server. After a while I get an java.net.ConnectException: Connection timed out exception.
What am I missing? Are there other ports that need to be opened?
Well, im pretty sure I had to open another port. Because when I opened all ports for incoming traffic, it worked.
Since this was only a test setup i lived with that and simply restricted incoming traffic to well known sources.