Network is unreachable - Ports Socket Client

[alecaus]

Hello,
I have an application in PHP, which creates a client (socket client) that connects to another site (a server client - socket).

In fact, I have several applications (30 or 50 more) that do this on the same server.

The point is, I can't connect a new client (from error: network unreachable) ...

Is this some centOS7 configuration?

When I reset the server and try to connect, it works. After a few hours, when I try to connect again, it doesn't work and the error returns: Network Unreachable

What can I be doing?