Stop http service, yum still work CentOS7

UNIX for Beginners Q & A
1

Can anyone explain me why yum still working when I stop http service on my localmachine.

If I'm not wrong, yum repository use port 80 and 443, so stop http service should technicly stop possibility to install packages ?

2

Seems you do not understand how a basic network client-server process works?

Isn't that right?

3

it is possible that I have a gap in knowledge.
I would be grateful if you could explain it briefly.

4

In general, all traffic on the Internet has a beginning and an end point Often, this is referred to as the client and the server.

The server listens on well known ports. The client generally uses whatever is available.

When you run HTTPD on your machine, it is generally acting as a client, listening on port 80, or port 443 if using SSL.

When you use YUM to access their repo services, their server is generally listening or port 80, or port 442 if using SSL.

So, when you block HTTPD on your computer, you are not blocking that service on another server, like YUM, because to access a repo like YUM or GIT you are acting as a client, accessing a server. When you block or disable HTTPD on your computer, you are simply blocking access to your server, locally.

You should probably do some homework and learn some basics about client-server processes.

1 Like
5

Thank you for helpful tips.
Greetings !

--- Post updated at 02:45 PM ---

Am I correct, if I want to use redhat repository on the client side have to listen on port 80 and 443 ?

""

    For up2date, yum, rhn_register, and satellite-sync to work correctly, the firewall must allow connections to:
        rhn.redhat.com on port 80 (http)
        rhn.redhat.com on port 443 (https)
        xmlrpc.rhn.redhat.com on port 80 (http)
        xmlrpc.rhn.redhat.com on port 443 (https)
        content-xmlrpc.rhn.redhat.com on port 80 (http)
        content-xmlrpc.rhn.redhat.com on port 443 (https)
        content-web.rhn.redhat.com on port 80 (http)
        content-web.rhn.redhat.com on port 443 (https)
        cdn.redhat.com on port 80 (http)
        cdn.redhat.com on port 443 (https)
""
6

No.

Clients do not "listen" on port 80 or 443, servers listen on them.

In general, client processes are not "listeners".

I would love to take all my time teaching you client server operations; but it is really better for you to learn about this yourself.

You cannot learn about this in 10 minutes. You need to read some books or watch 3 or 4 YT videos, or both.

I spend my time developing code. However, there may be others here at unix.com who have time to teach you client-server communications.

Sorry, I just do not have the time right now. However, I can answer one question a day if you want to ask me (maybe two at the most); but you could probably learn faster watching some YT videos.

7

Run

yum repoinfo

The listed http://server/ need to listen on port 80 and the listed https://server/ on port 443.