How can I open listen ports on an Amazon EC2 instance?

Solution 1:

There are a few possibilities here. First possibility is that you haven't set that port up as a listener in Apache, you can do this by adding a line like

Listen 8080

Into you Apache configuration file.

The second possibility is that UFW is running (ubuntu Firewall), you can disable this by running

sudo ufw disable

or add ports to it via

sudo ufw allow 8080

The last possibility is IPTables is blocking it, you would need to look at

sudo iptables -L

to get a list of rules and change them from there.