OS: CentOS 7

This is a question that is bordering on two issues. I have a docker machine running where I recently installed the PLEX container from linuxserver/plex. The current problem is that I cannot access the site to configure PLEX https://localhost:32400/web. In my attempts to determine why this is occurring, I noticed that port 32400 appeared to be closed even though it should've been opened when the container was created, I am using the host network.

I attempted to see if I could access the site using curl

curl -i http://localhost:32400 
curl -i

I then verified open ports with NMAP


Starting Nmap 6.40 ( http://nmap.org ) at 2019-01-18 12:52 CST
Nmap scan report for
Host is up (0.00049s latency).
Not shown: 999 closed ports
22/tcp open  ssh

Nmap done: 1 IP address (1 host up) scanned in 0.10 seconds

So clearly port 32400 is not open, so I went to firewall-cmd

#sudo firewall-cmd --get-active-zones
  interfaces: eno1

#sudo firewall-cmd --zone=public --add-port=32400/tcp --permanent
#sudo firewall-cmd --reload

I also checked to see if it was open

#sudo firewall-cmd --zone=public --list-ports

However, NMAP still shows its closed. Any idea why firewalld would show an open port on the docker host machine but it is actually closed? I'm not even sure this will get the site working for Plex.

Verification of what Kramer had suggested that it was possible my interface was not setup

# ip addr
3: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    inet brd scope global noprefixroute dynamic eno1

#firewall-cmd --zone=public --list-interfaces
  • I take it you are using --net=host in your docker command as recommended – sourcejedi Jan 18 '19 at 20:29
  • @sourcejedi Yes, that's correct but it doesn't seem to open any of the needed ports – JMeterX Jan 18 '19 at 20:36
  • 1
    A bit on the obvious side, but does netstat or ss report port 32400 as listening? – Haxiel Jan 19 '19 at 6:26

make sure the network interface is succesfully added to zone "public", normally only the default net card is (i.e. eth0). To add an interface with a zone:

#firewall-cmd --permanent --zone=public --add-interface=<interface_name>

To know what interfaces you have try:




add the interface provinding the IP

In the future, when posting the command you run, please also post the output of the command, that helps to understand and debug the problem.

HTH :)

| improve this answer | |
  • Updated post to reflect your recommendation, I did verify that the interface was correct but I've listed it out above as well – JMeterX Jan 18 '19 at 21:56

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