SSH basics

Question 1

SSH is a technology for connecting to a remote server and accessing a command line on that server, often in order to ad____ it.

Answer 1

SSH is a technology for connecting to a remote server and accessing a command line on that server, often in order to administer it.

Question 2

SSH is usually used to access servers running U___-like operating systems, but your own computer doesn’t have to be running U___ in order to use SSH

Answer 2

SSH is usually used to access servers running Unix-like operating systems, but your own computer doesn’t have to be running Unix in order to use SSH

Question 3

SSH is a secure protocol used as the primary means of connecting to Linux servers remotely. It provides a text-based interface by spawning a remote shell. After connecting, all commands you type in your local terminal are sent to the r____ s_____ and executed there.

Answer 3

SSH is a secure protocol used as the primary means of connecting to Linux servers remotely. It provides a text-based interface by spawning a remote shell. After connecting, all commands you type in your local terminal are sent to the remote server and executed there.

Question 4

When you connect through SSH, you log in using an account that exists on the r____ s_____.

Answer 4

When you connect through SSH, you log in using an account that exists on the remote server.

Question 5

When you connect through SSH, you will be dropped into a s___ session, which is a text-based interface where you can interact with your server.

Answer 5

When you connect through SSH, you will be dropped into a shell session, which is a text-based interface where you can interact with your server.

Question 6

For the duration of your SSH session, any commands that you type into your local terminal are sent through an encrypted SSH t____ and executed on your server.

Answer 6

For the duration of your SSH session, any commands that you type into your local terminal are sent through an encrypted SSH tunnel and executed on your server.

Question 7

For an SSH connection to be established, the remote machine must be running a piece of software called an SSH d_____

Answer 7

For an SSH connection to be established, the remote machine must be running a piece of software called an SSH daemon

Question 8

SSH keys are a matching set of c________ic keys which can be used for authentication

Answer 8

SSH keys are a matching set of cryptographic keys which can be used for authentication

Question 9

SSH keys are 2048 b__s by default. This is generally considered to be good enough for security, but you can specify a greater number of b__s for a more hardened key.

Answer 9

SSH keys are 2048 bits by default. This is generally considered to be good enough for security, but you can specify a greater number of bits for a more hardened key.

Question 10

To find out the fingerprint of an SSH key, type:

Answer 10

ssh-keygen -l

Question 11

To connect to a remote server and open a shell session there, you can use the s__ command.

Answer 11

To connect to a remote server and open a shell session there, you can use the ssh command.

ssh remote_host

Question 12

By default the SSH daemon on a server runs on port __

Answer 12

By default the SSH daemon on a server runs on port 22

Question 13

you will have to specify the new port number when connecting with your client, which you can do with the -_ option

Answer 13

-p option to specify port

Question 14

you can create or edit a configuration file in the ~/.ssh directory within the home directory of your local computer.

Edit or create the file now by typing:

Answer 14

nano ~/.ssh/config
OR
vim ~/.ssh/config

Question 15

to completely disable root login through SSH after you have set up an SSH user account that has sudo privileges, open the SSH daemon configuration file with root or sudo on your remote server do the following 3 things:

Answer 15

1)
sudo nano /etc/ssh/sshd_config
OR
sudo vim /etc/ssh/sshd_config

2)
PermitRootLogin no

To implement your changes, restart the SSH daemon
3)
sudo service ssh restart

Question 16

____ is the default location for SSH keys on Unix-based systems (like macOS and Linux). The ~ represents your h___ directory.

Answer 16

~/.ssh is the default location for SSH keys on Unix-based systems (like macOS and Linux). The ~ represents your home directory.

Question 17

SSH is used for remote file t_____, network m______, and remote o_____ s_____ access

Answer 17

SSH is used for remote file transfer, network management, and remote operating system access

Question 18

The private vs public nomenclature can be confusing as they are both called keys. It is more helpful to think of the public key as a “l___” and the private key as the “key”. You give the public ‘l___’ to remote parties to encrypt or ‘l___’ data. This data is then opened with the ‘private’ key which you hold in a secure place.

Answer 18

The private vs public nomenclature can be confusing as they are both called keys. It is more helpful to think of the public key as a “lock” and the private key as the “key”. You give the public ‘lock’ to remote parties to encrypt or ‘lock’ data. This data is then opened with the ‘private’ key which you hold in a secure place.

Question 19

SSH keys are used to a_____ s_____ connections

Answer 19

SSH keys are used to authenticate secure connections