Basic CentOS Setup Before Building A Working Server

it seems that the most basic thing is missing; how to actually install the OS itself, that I cannot find?? I am interested in learning how to install a centos LAMP from the netinstall to run headless.
A tutorial on that would be great! I love the other stuff that you have in your blog. it is the most comprehensive and well written, easy to understand blog I have ever come across. A lot of sites assume the user already knows the commands to edit and save configs, you don’t make that assumption and I love it for that!

Thanks for your Tut madame. but i have problems

Why I get error after doing this, when I open putty and access my server to the new port I configured.
Network Error: Connection timed out.,,

This is a great tutorial, thank-you heaps.

Great tutorial. You should also add how to forward the new SSH port in iptables though, many people might get locked out if they forget not to close their active section or if their computer crashes while they’re working on it. Thanks! 😉

I can’t $ su from the newly created user.

I fixed the issue with $ chmod 4755 /bin/su, is this ok security wise ?

thanks for the tutorial. I was greatly helped. I am also looking for the same tutorial for “debian OS”. hopefully I also find it here.

Thank you so much, I get it done easily..

mbaknya indonesia ya? lg bingung nih setup vps unmanaged saya

Tks for the nice tutorial.
I have one questions. when I upload the files by SFTP, it always says : Permission denied
Please help.
Tks

Excellent tutorials! Unfortunately,I set up my Digital Ocean VPS without changing my ssh port. I also installed fail2ban. Everything works.
When I now change the port number in the sshd config file and in Putty to a non-standard port, I can no longer connect with Putty.
I suspect I must do something with iptables and fail 2 ban as well to make this work.
Could you suggest how I could make this change?

Damn autocorrection on french mobile.please remove previous comment

Thanks!
I follow your steps, but i got a big problem!
Now when i want login in putty, appear this:

“Putty Fatal Error
Network Error: Connection refused”

How can i resolve? Please help me!

mom, I follow all your steps to change port and everything. Now I can’t log.in to my puTTy. What should I do? please help me.

THANKS,
jj

I have set centos 7 up locally on a spare laptop. followed along with a video that showed me how to install most stuff and I followed along with this page and I was having this same issue with not being able to ssh into the server once I changed the port to 22000 it would deny me. I finally found a page that instructed to install semanage and gave a couple commands which fixed the issue I also had to go change a line in iptables which had 22 in the entry I changed to 22000 and it all works. ( http://www.dropbit.ch/change-ssh-port-centos-7/ )
that page is where it said this: On a minimal CentOS 7 System the command “semanage” is missing therefore install it with “sudo yum install policycoreutils-python”
Afterwards you can use “semanage port -a -t ssh_port_t -p tcp 4444″, now SELinux allows sshd to listen on the new port 4444. which helped out on this one issue

i change ssh port 22 to 22000 and iptables off. But I can not log on ssh

Hey Mom,
You may add another step, i.e. to configure and open 22000 port in CentOS 6 or > version.

Here is what worked for me in CentOS 6.7, to open up the port for new user:

How to open a port in the firewall on CentOS or RHEL
Posted on October 26, 2014 by Dan Nanni 2 Comments
Question: I am running a web/file server on my CentOS box, and to access the server remotely, I need to modify a firewall to allow access to a TCP port on the box. What is a proper way to open a TCP/UDP port in the firewall of CentOS/RHEL?

Out of the box, enterprise Linux distributions such as CentOS or RHEL come with a powerful firewall built-in, and their default firewall rules are pretty restrictive. Thus if you install any custom services (e.g., web server, NFS, Samba), chances are their traffic will be blocked by the firewall rules. You need to open up necessary ports on the firewall to allow their traffic.

On CentOS/RHEL 6 or earlier, the iptables service allows users to interact with netfilter kernel modules to configure firewall rules in the user space. Starting with CentOS/RHEL 7, however, a new userland interface called firewalld has been introduced to replace iptables service.

To check the current firewall rules, use this command:
$ sudo iptables -L

Now let’s see how we can update the firewall to open a port on CentOS/RHEL.
Open a Port on CentOS/RHEL 7

Starting with CentOS and RHEL 7, firewall rule settings are managed by firewalld service daemon. A command-line client called firewall-cmd can talk to this daemon to update firewall rules permanently.

To open up a new port (e.g., TCP/80) permanently, use these commands.
$ sudo firewall-cmd –zone=public –add-port=80/tcp –permanent
$ sudo firewall-cmd –reload

Without “–permanent” flag, the firewall rule would not persist across reboots.

Check the updated rules with:
$ firewall-cmd –list-all
Open a Port on CentOS/RHEL 6

On CentOS/RHEL 6 or earlier, the iptables service is responsible for maintaining firewall rules.

Use iptables command to open up a new TCP/UDP port in the firewall. To save the updated rule permanently, you need the second command.

And also include this step:
How to login with new user created with new port:

For Putty, in Windows:
Just open putty, type your host server ip (and not domain name which is pointed to the host, since you have changed the value of “useDNS” to no in Step 5 above), and instead of default port “22” in the putty windows, type “22000” or your port.
Then, in the “login as” question, input new domain instead of root, as root Login has been disabled in step 5.

For Linux/Mac OS terminals:
1. Open Terminal.
2. Type the command:

ssh newuser@123.234.456.234 -p 22000
or
ssh 123.234.456.234 -p 22000
</code
Replace newuser with the username you just created. Replace 123.234.456.234 with your server host IP and NOT SERVER POINTED DOMAIN NAME. Replace 22000, with your open port, and saved port in Step 5.

Thanks,
(and WELCOME to the person being helped)

Hi,
How do I change default ssh22 to 2022 or any other port?

Steps I did:
1.Change SSH default port with /etc/ssh/sshd_config

2.Added the following commands to run
iptables -A INPUT -p tcp –dport 22 -j ACCEPT
iptables -A INPUT -p tcp –dport 80 -j ACCEPT
iptables -A INPUT -p tcp –dport 443 -j ACCEPT
iptables -A INPUT -p tcp –dport 110 -j ACCEPT
iptables -A INPUT -p tcp –dport 465 -j ACCEPT
iptables -A INPUT -p tcp –dport 143 -j ACCEPT
iptables -A INPUT -p tcp –dport 993 -j ACCEPT
iptables -A INPUT -p tcp –dport 587 -j ACCEPT
iptables -A INPUT -p tcp –dport 25 -j ACCEPT
iptables -A INPUT -p tcp –dport 995 -j ACCEPT
iptables -A INPUT -m state –state RELATED,ESTABLISHED -j ACCEPT
iptables -A INPUT -j REJECT
iptables -A FORWARD -j REJECT

3.Saved the iptables

4.Updated firewall settings for new port by
deleting this
iptables -A INPUT -p tcp –dport 22 -j ACCEPT
adding this
-A INPUT -m state –state NEW -m tcp -p tcp –dport 2022 -j ACCEPT

4.Restarted iptables

5.Restarted ssh service

Issue:
Then if I try to login using 22ssh it gives me connection timeout.
The same I try to do with 2022ssh it also gives me connection timeout.

Kindly help.

Much Thanks in advance.

Hey
thanks for your good blog 😡

Hi
I did add another user like you said but when I want to get root back it I can’t I changed PermitRootLogin to yes but still can’t log in as root