Cant connect express app - node.js

Question

Locally I can connect to my express app on port 9000. If I start it on remote server I am unsuccessful to reach app, but I see in console logs that it successfully starts.
I see next output for netstat command after $my-express-app pm2 start bin/www
tcp6 0 0 :::3000 :::* LISTEN 52407/www
tcp6 0 0 :::8000 :::* LISTEN 43298/server.js
tcp6 0 0 :::9000 :::* LISTEN 52407/www
And next if I start as $my-express-app pm2 start app.js
tcp6 0 0 :::8000 :::* LISTEN 43298/server.js
tcp6 0 0 :::9000 :::* LISTEN 53096/app.js
My setup configuration is next
...................
app.set('port', 9000)
...................
app.listen(app.get('port'));
Have I missed something?
Express version is 4.x
Update
I also tried to bind app to listen any ip app.listen(app.get('port'),'0.0.0.0')
I have add 2 input/output rules (udp rule was exist before)
Chain INPUT (policy ACCEPT)
target prot opt source destination
ACCEPT tcp -- anywhere anywhere tcp dpt:9000
ACCEPT udp -- anywhere anywhere udp dpt:bootpc
Chain FORWARD (policy ACCEPT)
target prot opt source destination
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
ACCEPT all -- anywhere anywhere
ufw status tells me it inactive.
Have no sucess. Environment ubuntu 14.04
Update
I was able to run app on port 8000, where other js app is running normally. I cant find any settings related to this port. 9000 still not works. Below is nmap scan for 9000 port
nmap -p 9000 127.0.0.1
Starting Nmap 6.40 ( http://nmap.org ) at 2017-10-04 08:52 UTC
Nmap scan report for localhost (127.0.0.1)
Host is up (0.000070s latency).
PORT STATE SERVICE
9000/tcp open cslistener
Nmap done: 1 IP address (1 host up) scanned in 0.05 seconds
nmap -p 9000 myip
Starting Nmap 6.40 ( http://nmap.org ) at 2017-10-04 08:52 UTC
Note: Host seems down. If it is really up, but blocking our ping probes, try -Pn
Nmap done: 1 IP address (0 hosts up) scanned in 3.05 seconds
RESOLVE
I need to setup endpoint to port 9000 on azure portal. It works now. Thanks.

Answer 1

You should check your remote server firewall and add the port 9000 to be opened for traffic.

Answer 2

What operating system are you using, and who is hosting this server for you? For example, I know that if you rent an Ubuntu server on DigitalOcean, most ports (including 9000) will be blocked by default by the firewall, ufw. If you're running on a new-ish version of Ubuntu, you can check your current firewall rules with ufw status. You may have to modify your firewall rules with ufw allow 9000.