Hi,

I have opened port using firewall-cmd command like below:

firewall-cmd --zone=work --add-port=443/tcp --permanent

firewall-cmd --reload


firewall-cmd --list-ports
443/tcp

It showing 443/tcp is opned.

but when i check in below command

port 443 is not showing.

netstat -lntu


I want to enure port is opened from operating system end.


please help

Hi,
Opening a port on firewall is one part. You also need a service listening on that port.
By default a ssl-enabled webserver is listening on port 443, so use your package manager to install and configure a ssl capable webserver (like apache, nginx, etc)

Regards

As Bathory mentioned there should be an application listening to that port or utilizing 443 port.

Why did you open port 443? The application suppose to use 443, is it running?

Hi All,

I opened port because external application is going to access my os using port 443. so just want to know it is opened from my OS end

Without something listening on port 443 they are not going to connect to anything. This is why you cannot verify the port is open and the same reason a hacker cannot detect it.

If external application is going to access via port 443, then an internal application should be ready to receive the request of the external application.

A logic would be like an Infrared, there's a transmitter and a receiver. Same logic goes with the network ports, external application connect to port 443 and internal application application ready to process the connection on port 443.

Quote above from this link: https://www.grc.com/port_443.htm

But if the external application is one of a kind that connects to port 443 on your network, and even though nothing is listening on port 443 and the application is able to connect to your internal network and control whatever it can control, then I think it's pure awesomeness and scary moment. Run or turn off the power or simply cut all the cables with a bolt cutter.

1 members found this post helpful.

Thanks a lot for all your Info's

what about using NMAP tool? cant we detect port open status using NMAP ?

Again, nmap won't detect that the port is open unless something is listening on it.
Again, port 443 is for the secure http [https] server.
You will need to configure and run a secure web server to be able to have "external application" connect to it.
-or-
What JJJCR said:

Okay what's your Public IP we will do it for you? hahaha

Nmap can detect of course as long as everything is setup properly.

If everything is not setup properly no any tool in this planet earth, can tell whether that port is open or not.

Here's an exercise, use any tool you want and check whether Port 80 is open or not, if it is open then check 443, if it is not open try accessing: https://www.duckduckgo.com

Check whether you can access or not.

BTW, your setup is something like this:

Linux BOX <---> Router <---> ISP / External Network

Or there is something in between the router?