Is port open automatically on linux?

[Orochimaru]

I have an application to deliver the traffic from Server-A to Server-B.
On Server-A : delivers traffic though from port 10000 till port 19000 randomly
On Server-B (Centos 7)
- receives the traffic from port 10000 till port 19000
- no firewall installed and no restriction on https://speedtest.vet/ https://vidmate.bid/ a specific port on this server

During the test, I need to capture the traffic on Server-B using tcpdump : tcpdump -i eth1 portrange 10000-19999 -s0 -w /tmp/pcap-test.pcap

In order to test the traffic delivery from Server-A to Server-B :
- Should I open the port (from port 10000 till port 19000) on Server-B? Or the port will open automatically since no firewall on Server-B?
If yes, how to open multiple ports using range on Centos 7?
- Should I use Socat command to open the port?

Thanks.

 

[dos2unix]

Usually not. All of the major distro's I am aware of have firewalls.

In CentOS 7 you can use iptables. I myself prefer firewall-cmd.

Depending on where the files are and what permission they have you may also
have play with SElinux permissions.

 

[f33dm3bits]

In CentOS 7 you can use iptables. I myself prefer firewall-cmd.

nftables is the new thing, firewalld use it as well as it is a front-end for nftables.