Exercise: Log in and find your way

Open a shell on workstation, read the prompt, hop to both servers with SSH, become root and come back. Nothing here changes the lab, so you can repeat it as often as you like.

Log in and find your way

Open a shell on workstation and read its prompt.
Log in to the servers with SSH and recognise a first-connection warning.
Switch to root and back, and log out.

Host: open a shell on workstation

On the Ubuntu host, run:

<HOST_USER>@host:~$ rht-vmctl ws
[student@workstation ~]$

Read the prompt aloud: you are student, on workstation, in your home directory (~), as an ordinary user ($). Every later task runs here unless it says otherwise.

Workstation: ask the system who and where you are

Three small commands answer the questions the prompt abbreviates:

[student@workstation ~]$ whoami
student
[student@workstation ~]$ hostname
workstation.lab.example.com
[student@workstation ~]$ date
Sat Oct  3 09:30:23 AM UTC 2026

hostname prints the full name; the prompt shows only the part before the first dot. Your date and time will differ: the lab's clock runs in UTC.

Workstation: log in to servera

Your SSH key from chapter 1 logs you in without a password. Watch the hostname in the prompt change:

[student@workstation ~]$ ssh student@servera
Last login: Sat Oct  3 09:30:04 2026 from 172.25.250.9
[student@servera ~]$ hostname
servera.lab.example.com

Last login tells you when this account last logged in, and from where. It is worth a glance on a real server: a login you don't recognise is a reason to investigate.

servera: become root, then go back

sudo -i asks for your password (student) and opens a root shell. The very first time an account uses sudo on a machine, sudo also prints a short reminder to respect others' privacy and think before you type; you saw it in chapter 1 when you set up the keys.

[student@servera ~]$ sudo -i
[sudo] password for student:
[root@servera ~]# whoami
root
[root@servera ~]# exit
logout
[student@servera ~]$

The prompt ends in # while you are root. exit returns you to student, still on servera.

servera: log out with Ctrl+D

Press Ctrl+D at the prompt. It means "end of input", and the shell treats it like exit:

[student@servera ~]$ logout
Connection to servera closed.
[student@workstation ~]$

Workstation: meet a first-connection warning

Your account has seen serverb's host key under its names, but not under its IP address, so connecting by address triggers the first-connection check. Read the whole message before answering yes:

[student@workstation ~]$ ssh student@172.25.250.11
The authenticity of host '172.25.250.11 (172.25.250.11)' can't be established.
ED25519 key fingerprint is SHA256:7N7t4m6HkSRbZBH7LwIPFphA74uWFmwfY/AJmjjLVqs.
This host key is known by the following other names/addresses:
    ~/.ssh/known_hosts:5: serverb.lab.example.com
    ~/.ssh/known_hosts:8: serverb
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '172.25.250.11' (ED25519) to the list of known hosts.
[student@serverb ~]$

SSH helpfully points out that the same key is already trusted under serverb's names, which is good evidence that this really is serverb. Your fingerprint and line numbers will differ.

Every machine generates its own host keys when it is first installed. If you rebuild servera, the new servera has new keys, and SSH refuses to connect until you remove the old entry with ssh-keygen -R servera. On a real network, a key that changes without a rebuild is a warning sign.

serverb: log out

[student@serverb ~]$ exit
logout
Connection to 172.25.250.11 closed.
[student@workstation ~]$

You are back on workstation. Nothing in this exercise changed the servers, so there is nothing to reset.