Network connections are a fundamental aspect of any operating system, including Linux. Understanding how to manage these connections is crucial for systems administrators, network engineers, and anyone responsible for maintaining the health and security of a networked environment. This article will guide you through the essential commands and configurations for managing network connections in Linux. We'll cover how to view network configurations, set up new connections, and troubleshoot common network issues.

Examples:

1. Viewing Network Configuration: To view the current network configuration, you can use the ifconfig or ip command.

   # Using ifconfig
   ifconfig
   
   # Using ip
   ip addr show

   These commands will display the IP addresses, subnet masks, and other network interface details.

2. Setting Up a New Network Connection: To configure a new network connection, you can use the nmcli command, which is part of the NetworkManager tool.

   # Create a new connection
   nmcli con add type ethernet ifname eth0 con-name my-eth0
   
   # Configure IP address
   nmcli con modify my-eth0 ipv4.addresses "192.168.1.100/24"
   nmcli con modify my-eth0 ipv4.gateway "192.168.1.1"
   nmcli con modify my-eth0 ipv4.dns "8.8.8.8 8.8.4.4"
   nmcli con modify my-eth0 ipv4.method manual
   
   # Bring up the connection
   nmcli con up my-eth0

3. Troubleshooting Network Issues: If you encounter network issues, tools like ping, traceroute, and netstat can be invaluable.

   # Check connectivity to a host
   ping google.com
   
   # Trace the route to a host
   traceroute google.com
   
   # Display network connections, routing tables, interface statistics, masquerade connections, and multicast memberships
   netstat -tuln

4. Managing Network Services: Sometimes network issues are related to services. You can manage network services using systemctl.

   # Restart the NetworkManager service
   sudo systemctl restart NetworkManager
   
   # Check the status of the NetworkManager service
   sudo systemctl status NetworkManager