networking - Linux port open locally, but not externally

Port is open locally, but not externally

Neo4j is a graph database with a browser and REST interface.I need to start a second instance of neo4j server. I would like to run the process a user with normal privileges.

The first instance of neo4j opens the default port for neo4j, 7474, and runs and HTTP server on it. I can reach it with a Web browser from another machine. That's great.

The second instance is configured to use a different port, 7484. I can start the server and reach it locally:

 >lynx http://localhost:7484

That's great too.

However, if I use another machine and try to browse http://my-neo4j-server:7484, the browser times-out and never establishes a connection.

If I run netstat on the server, it shows that it is listening on that port.

 >netstat -tulpn 

...

tcp6  0  0   :::7484   :::*  LISTEN  8552/java

I tried:

  >sudo ufw disable

I checked IP tables:

>sudo iptables -L

and there are no entries in the tables.

What am I failing to do?

Note: I'm running the Amazon Linux AMI on ec2.

Answer

AWS has its own firewall and security group. You need to open the port there too.

For EC2, you can go to Service -> EC2 -> Network & Security -> Security Groups and open the port for the right group.