Linux Service Guides

This guide provides detailed configuration and usage for three common Linux services. Click the tabs below to view the different service guides.

SSH

SSH Service Guide

SSH (Secure Shell) is a secure protocol for remote login and other network services. It provides an encrypted communication channel.

Note

SSH has become the standard tool for Linux/Unix system administration, replacing insecure protocols such as Telnet and rlogin. Beyond remote login, it also supports file transfer, port forwarding and more.

Installing SSH

On most Linux distributions you can install the SSH service with the package manager.

On Debian/Ubuntu

sudo apt update
sudo apt install openssh-server

On CentOS/RHEL

sudo yum install openssh-server

Configuring SSH

The SSH configuration file is located at /etc/ssh/sshd_config.

Sample configuration

# Port number
Port 22

# Listen addresses
ListenAddress 0.0.0.0
ListenAddress ::

# Allowed users
AllowUsers user1 user2

# Disable password authentication, key authentication only
PasswordAuthentication no
PubkeyAuthentication yes

# Enable X11 forwarding
X11Forwarding yes

# Log level
LogLevel INFO

Explanation

• Port: the port the SSH service listens on.
• ListenAddress: the addresses the SSH service listens on.
• AllowUsers: the list of users allowed to log in.
• PasswordAuthentication: whether password authentication is allowed.
• PubkeyAuthentication: whether public key authentication is allowed.
• X11Forwarding: whether X11 forwarding is enabled.
• LogLevel: the log level.

Starting and Managing the SSH Service

sudo systemctl start ssh    # start the service
sudo systemctl enable ssh   # enable on boot
sudo systemctl status ssh   # check service status

Using SSH

Connect to a remote server:

ssh username@hostname

Generate an SSH key pair:

ssh-keygen -t rsa -b 4096 -C "your_email@example.com"

Copy the public key to the remote server:

ssh-copy-id username@hostname

@tab Samba

Samba Service Guide

Samba implements the SMB/CIFS protocol, enabling file and printer sharing between Linux and Windows systems.

Installing Samba

On Debian/Ubuntu

sudo apt update
sudo apt install samba

On CentOS/RHEL

sudo yum install samba

Configuring Samba

Edit the configuration file:

sudo nano /etc/samba/smb.conf

Add a shared directory:

[share]
   comment = Shared Directory
   path = /srv/share
   browseable = yes
   read only = no
   valid users = user1

Set the Samba password for the user:

sudo smbpasswd -a user1

Starting and Managing Samba

sudo systemctl start smbd
sudo systemctl enable smbd
sudo systemctl status smbd

Accessing from Windows

Open the file explorer and visit \\<server-ip>\share, then log in with the Samba username and password.

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