RH124 - ch09s07

Students will set up SSH keys, configure and exclusively allow user key-based authentication, and lock down the OpenSSH service to prevent the root user from logging into the system by using SSH.

Reset the desktopX and serverX systems.

Run lab ssh setup as the student user on both desktopX and serverX. This will create a user account called visitor with a password of password.

[student@desktopX ~]$ lab ssh setup

[student@serverX ~]$ lab ssh setup

Unless specified, all steps are to be performed as user visitor.

Generate SSH keys on desktopX for user visitor and copy the public key to the visitor account on serverX.

Generate a SSH public key on desktopX as user visitor.
```
[visitor@desktopX ~]$ ssh-keygen
```

Install the SSH public key generated previously on desktopX to the visitor account on serverX.

[visitor@desktopX ~]$ ssh-copy-id serverX
The authenticity of host 'serverX (172.25.X.11)' can't be established.
ECDSA key fingerprint is xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx.
Are you sure you want to continue connecting (yes/no)? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
visitor@serverX's password: password

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh 'visitor@serverX'"
and check to make sure that only the key(s) you wanted were added.

Disable ssh login for the root user and password-based SSH authentication on serverX.
Log into the serverX virtual machine as user root.
[visitor@desktopX ~]$ ssh root@serverX
Customize the ssh service on serverX by disabling SSH connections for the user root and only allow key-based login.
Set the necessary config file parameters in /etc/ssh/sshd_config:
PermitRootLogin no PasswordAuthentication no

Restart the sshd service on serverX.
[root@serverX ~]# systemctl restart sshd
Verify that user root is not allowed to login to serverX by using ssh, while user visitor is with the private key.
On a different terminal window on desktopX, validate that user root cannot connect to serverX with the ssh command. It should fail because we disabled root logins with the ssh service.
[visitor@desktopX ~]$ ssh root@serverX Permission denied (publickey,gssapi-keyex,gssapi-with-mic).
Try logging in as user student to serverX from desktopX by using ssh. It should fail because we did not add the public key from that user to the student account on the serverX machine.
[visitor@desktopX ~]$ ssh student@serverX Permission denied (publickey,gssapi-keyex,gssapi-with-mic).
Verify the ssh service is still accepting key-based authentication by successfully connecting to serverX as user visitor with the ssh command.
[visitor@desktopX ~]$ ssh visitor@serverX [visitor@serverX ~]$

Discuss Red Hat System Administration I

Go to community

RH124 Chapter 15 Lab 3: Install zsh Package

VictoriaB97

16 sty 2024

Hello,I am trying to finish up Lab 3 of the Chapter 15 Comprehensive Review Labs in RH124, and when I type in sudo dnf install zsh for the 6th specification of the lab, I get an error message basically saying that it failed to download metadata for the repo 'ansible-2.9-for-rhel-9-x86_64-rpms', and that they could not download repomd.xml. It provided a 404 status code.Can someone please let me know what the problem is, and if there is a current workaround? Thanks.

378

Red Hat System Administration I | Guided Exercise: Explain and Investigate RPM Software Pack

AbeHiero

10 lis 2023

I cannot start the lab with command: lab start software-rpm. I get this error:ModuleNotFoundError: No module named 'rhcsa-classroom'Script software-rpm not in course library rhcsa-classroom Anyone else see this?

172

Red Hat System Administration I (RH124)

Haley_Ruccio

19 lip 2023

The first of two courses covering the core system administration tasks needed to manage Red Hat Enterprise Linux serversRed Hat System Administration I (RH124) is designed for IT professionals without previous Linux system administration experience. The course provides students with Linux administration competence by focusing on core administration tasks. This course also provides a foundation for students who plan to become full-time Linux system administrators by introducing key command-line concepts and enterprise-level tools. This course is the first of a two-course series that takes a computer professional without Linux system administration knowledge to become a fully capable Linux administrator. These concepts are further developed in the follow-on course, Red Hat System Administration II (RH134).This course is based on Red Hat® Enterprise Linux 9.0.Course content summaryIntroduce Linux and the Red Hat Enterprise Linux ecosystem.Run commands and view shell environments.Manage, organize, and secure files.Manage users, groups and user security policies.Control and monitor systemd services.Configure remote access using the web console and SSH.Configure network interfaces and settings.Manage software using DNFAudience for this courseThe primary persona is a technical professional with current or pending responsibilities as a Linux enterprise or cloud system administrator.This course is popular in Red Hat Academy, and is targeted at the student who is planning to become a technical professional using Linux.Prerequisites for this courseBasic technical user skills with computer applications on some operating systems are expected.Take our free assessment to gauge whether this offering is the best fit for your skills.Technology considerationsThere are no special technical requirements for this course.This course is not designed for bring your own device (BYOD).Internet access is not required but is recommended so that students can research and browse Red Hat online resources.

336

Revision: rh124-7-1b00421