- A Cloud Guru
Locking Down Remote Access to Linux
In this lab, we will look at how to lock down remote access to a Linux host. We will accomplish this by restricting all remote logins for the `root` account as well as restricting SSH access based on account names.
Table of Contents
Prevent remote logins from using the `root` account.
In order to prevent remote logins from using the
rootaccount, we'll need to edit the
/etc/passwdfile. Run the following command:
- select #2 for nano (easiest)
Next, edit the line that starts with
Save and exit the
Permit only the `cloud_user` account to connect to the host via SSH.
In order to filter SSH access and only permit the
cloud_useraccount to access the host via SSH, we'll need to edit the
sshd_configfile with the following command:
sudo nano /etc/ssh/sshd_config
Add the following line to the file just under the second line of the file:
Note: You can also restrict user access by source hostname, IP address, or subnet, like:
AllowUsers [email protected]/24 AllowUsers [email protected] AllowUsers [email protected]
Now, restart the
sshservice with the following command:
sudo service ssh restart
What's a lab?
Hands-on Labs are real environments created by industry experts to help you learn. These environments help you gain knowledge and experience, practice without compromising your system, test without risk, destroy without fear, and let you learn from your mistakes. Hands-on Labs: practice your skills before delivering in the real world.