How to open another port?


New Member
It looks like my old post disappeared. Search profile posts says I am not found. So I am starting a new post.

I have VPS with fresh install of debian 11. I have open port: 22 Secure Shell (SSH). I have closed port: 25 Simple Mail Transfer Protocol (SMTP). I am trying to open port 25. I am not try to change the port numbers, I am simply trying to open one more port. As one port is open and the rest are closed, I guess that a firewall is installed and running. Or what else can cause this? And how to fix this?
You mean this thread?

Is your running daemon even bound to the port? There's no such thing as like 'an open port to a process that doesn't exist'.
Yes, thank you johnb35. I could not find it because it is in General Software. Search profile posts did not find it. How can I find my posts? And now it is a little outdated. I might go back to it later. My new post is OK with me. It is current and specific. If it will help, I can detail all the things I tried.
Search profile posts did not find it. How can I find my posts?
Your profile posts are exactly that, profile posts. Your forum posts you can find by seeing the attached image. click on your username and you'll see a page similar to this minus a few things. Look at the find box I have opened.

find content.jpg
Thank you johnb35.
To beers: I guess running daemon means a process like firewall. I can not find the running daemon that is causing this problem. If I do find it, then I can check if it is bound to the port (whatever that means.) Sorry I am new to these terms. It sounds like you are asking about one of these: /etc/services, netstat, ss, lsof. Can you give me more details of how to check?