I am trying to connect to a new CentOS 7 server to do some performance testing. It is a minimal install and at this point the only things installed / configured are to test RAID performance, Java 1.7 and Wowza Media Server which has a web service that runs on port 8088. I am able to SSH / Sftp into the server all I want, but can't connect to the port 8088 from my windows computer.

The 2 computers are on the same network, and the switch has that port open as I can tie into the Ubuntu server sitting next to it on port 8088. Using the lynx command line browser on the CentOS server, I can open the site using localhost, or it's IP address as well. There are no rules configured by me in iptables or /etc/hosts.deny. I have looked at all the tips I could think of to see what is open using netstat, or nmap and don't see what is going on. What am I missing here?

You can see port 8088 open here:

[root@localhost sysconfig]# netstat -tanp | grep LISTEN
tcp        2      0  *               LISTEN      2490/master         
tcp        0      0    *               LISTEN      1694/sshd           
tcp        0      0  *               LISTEN      1781/java           
tcp6       0      0 ::1:25                  :::*                    LISTEN      2490/master         
tcp6       0      0 :::22                   :::*                    LISTEN      1694/sshd           

[root@localhost sysconfig]# nmap -sT -O
Starting Nmap 6.40 ( http://nmap.org ) at 2015-01-06 11:05 MST
Nmap scan report for
Host is up (0.0024s latency).
Not shown: 998 closed ports
22/tcp   open  ssh
8088/tcp open  radan-http
Device type: general purpose
Running: Linux 3.X
OS CPE: cpe:/o:linux:linux_kernel:3
OS details: Linux 3.7 - 3.9
Network Distance: 0 hops
  • 1
    Chances are you will have firewalld running by default on the server which will be blocking non-standard ports. You can check if firewalld is running by using the command firewall-cmd --state Commented Jan 6, 2015 at 18:24
  • (1) what's the output from iptables -nL? (2) is Wowza media server running from xinetd? (3) if you run telnet centhost 8088 do you see a connection? Commented Jan 6, 2015 at 18:25

1 Answer 1


Turns out it was a firewall configuration from the default installation. Live and learn. This is what I ended up finding: https://www.centos.org/forums/viewtopic.php?f=47&t=47129

firewall-cmd --zone=public --permanent --add-port=8088/tcp

Note that you have to restart the service before you can see the changes.

If you want to test it without restarting the service, you can remove the --permanent flag; however, the rule will expire as soon as the service restarts.

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