Connecting to Linux

4. On a server where no GUI is operational, what would you expect to be the device name that is used by the first SSH session that is opened to that server?

/dev/pts/0

2. Which is the correct word for the description here? "The environment from which a shell is used where users can enter their commands" a. Terminal b. Console c. Shell d. Interface

A

5. Which of the following methods will open a pseudo terminal device? a. Log in using an SSH session b. Use Alt+F2 to open a new nongraphical login c. Right-click the graphical desktop and select Open in Terminal d. Enter your username and password on a nongraphical console

A

There are two requirements for starting graphical applications through an SSH connection:

An X server must be running on the client computer. The X server is the software component that creates the graphical screens. The remote host must be allowed to display screens on the local computer.

1. Which is the correct word for the description here? "Used to refer to the physical screen you are currently looking at as a user?" a. Terminal b. Console c. Shell d. Interface

B

4. Which device file is associated with the virtual console that is opened after using the Alt+F6 key sequence? a. /dev/console6 b. /dev/tty6 c. /dev/vty6 d. /dev/pts/6

B

10. Which of the following statements about key-based SSH authentication is true? a. After creating the key pair, you need to copy the private key to the remote server. b. Use scp to copy the public key to the remote server. c. Use ssh-copy-id to copy the public key to the remote server. d. Use ssh-keygen on the server to generate a key pair that matches the client keys.

C

3. Which is the correct word for the description here? "The environment that offers a command line on which users type the commands they want to be using" a. Terminal b. Console c. Shell d. Interface

C

7. Which of the following is true about remote access to Linux servers from a Windows environment? a. Open a shell terminal on Windows and type ssh. The ssh command is available as a default part of the Windows operating system. b. Configure Remote Access on Windows if you want to access Linux servers running the sshd process. c. Install the PuTTY program on Windows to access sshd services on Linux from Windows. d. You cannot remotely access Linux machines from Windows.

C

9. To allow graphical applications to be used through an SSH session, you can set a parameter in the /etc/ssh/ssh_config file. Using this parameter makes it unnecessary to use the -X command-line option each time an SSH session is initiated. Which of the following parameters should be used? a. Host * b. TunnelX11 yes c. ForwardX11 yes d. Xclient yes

C

2. On a server that currently has an operational graphical interface, you are on a text-based login prompt. Which key sequence do you use to switch back to the graphical interface?

Ctrl+Alt+F1

6. Sometimes a server reboot may be necessary. Which of the following is not typically one of them? a. To recover from serious problems such as server hangs and kernel panics b. To apply kernel updates c. To apply changes to kernel modules that are used and because of that cannot be reloaded easily d. To apply changes to the network configuration

D

8. What is the name of the file in which the public key fingerprint of the SSH servers you have connected to in the past are stored? a. /etc/ssh/remote_hosts b. /etc/ssh/known_hosts c. ~/.ssh/remote_hosts d. ~/.ssh/known_hosts

D

As root, open the configuration file /etc/ssh/ssh_config and make sure it includes the following line:

ForwardX11 yes

1. What is the console?

Typically, the main screen on a Linux server

Notice that ssh uses -p (lowercase) to specify the port it needs to connect to; the scp command uses

an uppercase -P.

To force a machine to reset, you can use_____as a last resort.

echo b > /proc/sysrq-trigger

You can also use scp to copy an entire subdirectory structure. To do so, use the -r command, as in the following command:

scp -r server2:/etc/ /tmp

8. How do you copy over the /etc/hosts file to the directory /tmp on server2 using the username lisa?

scp /etc/hosts lisa@server2:/tmp

To copy, for instance, the /etc/hosts file to the /tmp directory on server2 using your current user account, use the following command:

scp /etc/hosts server2:/tmp

If you want to connect to server2 as user root to copy the /etc/passwd file to your home directory, you use the following command:

scp root@server2:/etc/passwd ~

6. How do you initiate an SSH session with support for graphical applications?

ssh -X

Use_________if you want to connect as linda to server2, and also be able to start graphical applications.

ssh -X linda@server2

5. Which command would you use to get detailed information on what SSH is doing while logging in?

ssh -v

Command to ssh into remoteserver as root.

ssh remoteserver -l root

10. Which command enables you to generate an ssh public/private key pair?

ssh-keygen

As an administrator, you can also create a systemwide configuration that allows you to use "X forwarding," which is

starting graphical applications through an SSH session

3. What command(s) shows all users that currently have a terminal session open to a Linux server?

w or who

9. What is the name of the file in which public keys are stored for remote users who want to log in to this machine using key-based authentication?

~/.ssh/authorized_keys

After copying over the public key to the remote host, it will be written to the

~/.ssh/authorized_keys file on that host

If a previously good address is not good, you just have to remove the key fingerprint from the ______ file.

~/.ssh/known_hosts

7. What is the name of the configuration file that needs to be edited to modify SSH client settings?

~/.ssh/ssh_config