Ubuntu Server 20.04 : SSH Service & Firewall
1. SSH service security settingsThe SSH service allows root user login by default.Since the root user already knows the username, if the password is known, he can log in to the server with administrator rights.1.1 Creating a general userIf you have created a general user during the installation of Ubuntu 20, this step is not necessary.If the only user created on the server is root, you will not be able to log in remotely via SSH, so if you have not created a user when you installed the OS, you will need to create one beforehand.To create a user, use the "useradd" command.The "-m" option is used to create a home directory and the "-p" option is used to specify a password.For example, to set "ubuntuuser" as the user account name and "123456" as the password, you would run
2021.12.17
Ubuntu20.04_en