[SOLVED] What might be blocking sockets only on certain ports?

NotionCommotion · 05-24-2017, 05:16 PM

I have a socket server listening to 0.0.0.0:80. I can connect to it from a socket client operating on another machine using 1.2.3.4:80 (where 1.2.3.4 is the server's IP).

Then I change from port 80 to 1337, and can no longer connect. The firewall is disabled. But I can connect if the client is operating on the same machine as the server.

It is a new server operating Centos7. My old Centos6 server did accept connections.

What should I investigate? Thank you

hydrurga · 05-24-2017, 05:35 PM

Is SELinux blocking access to the port?

NotionCommotion · 05-24-2017, 06:58 PM

Quote:

Originally Posted by hydrurga

Is SELinux blocking access to the port?

Damn that SELinux! I bet you are right.

I've never messed around with it much. In the past, I always disabled it, but really wanted to give it a closer look and determine whether I start using it.

NotionCommotion · 05-24-2017, 09:11 PM

Nope, sestatus shows SELinux status as being disabled. I was sure you were right!

NotionCommotion · 05-24-2017, 10:53 PM

Turned out to be a physical firewall above my virtual server.

hydrurga · 05-25-2017, 03:36 AM

Quote:

Originally Posted by NotionCommotion

Turned out to be a physical firewall above my virtual server.

Glad you found the problem.

Can you mark the thread as "Solved"? (see "Thread Tools" at the top of the thread)

Onwards and upwards!