6. Basic Networking

Summary

This video tutorial explains basic networking concepts, focusing on network configuration methods such as using `nmcli` for Red Hat-based systems and `netplan` for Ubuntu systems. It walks viewers through configuring network settings on a virtual machine in VirtualBox, including switching the network adapter to Bridged mode, assigning a static IP address, setting the gateway, and configuring DNS. The tutorial also covers using commands like `ip a`, `ping`, and `traceroute` to test and manage the network. This clear, step-by-step guide helps users understand how to configure networking on Linux systems.

Takeaways

• 😀 NMCLI is used for network configuration in Red Hat-based distributions, while Netplan is used for Ubuntu systems.
• 😀 Key network management commands include 'ip a' to view IP addresses, 'ping' to test connectivity, and 'traceroute' to analyze network routes.
• 😀 For VirtualBox VMs, changing the network adapter to 'Bridge' mode allows the VM to use an IP address from the local network (Wi-Fi or LAN).
• 😀 Static IP addresses are essential for servers to maintain consistent networking and avoid DHCP IP changes.
• 😀 Use the 'ip a' command to find the current server IP and edit the Netplan configuration file to change it.
• 😀 The default gateway can be found using the 'ip r' or 'ip route' command, and this must be specified in the Netplan configuration.
• 😀 Ubuntu 22 and above use 'routes' for setting gateways, while versions 20 and below use 'gateway4'.
• 😀 DNS servers like Google's (8.8.8.8) can be set in the Netplan configuration to ensure proper network resolution.
• 😀 After editing network configurations, the 'sudo netplan apply' command must be used to apply the changes.
• 😀 Verify networking changes by using 'ip a' and testing connectivity with 'ping google.com'.
• 😀 Traceroute can be installed and used to see the path packets take to reach destinations, useful for troubleshooting network issues.

Q & A

What are the methods for configuring a network mentioned in the script?

The script mentions two methods for configuring the network: using nmcli (Network Manager Command Line Interface) for Red Hat-based distributions, and using netplan for Ubuntu systems.

What commands can be used for network management and configuration?

The script mentions the commands 'ip', 'ifconfig', 'traceroute', and 'ping' for network management and configuration. These commands are used to check the configuration, execute root-level operations, and test connectivity.

How do you change the network adapter settings in VirtualBox for a VM running Ubuntu?

To change the network adapter settings in VirtualBox for a VM running Ubuntu, you should go to the VM settings and switch the network adapter from 'NAT' to 'Bridge'. This allows the VM to use an IP address from the local network.

What is the purpose of using a 'Bridge' network adapter in VirtualBox?

The 'Bridge' network adapter allows the VM to obtain an IP address from the local network, which means it will be treated as a regular device on the network, similar to a physical machine connected via Wi-Fi or LAN cable.

How can you find the IP address of your server in Ubuntu?

You can find the IP address of your server in Ubuntu by running the 'ip -a' command, which displays the network configuration, including the assigned IP address.

What is the default behavior of network configuration in Ubuntu when using DHCP?

In Ubuntu, the default network configuration is usually set to use DHCP, which automatically assigns an IP address to the system. This is suitable for environments where the IP address does not need to be static.

How can you set a static IP address for a server in Ubuntu?

To set a static IP address in Ubuntu, you need to edit the configuration file located in the /etc/netplan directory, change the DHCP setting to a static IP, and specify the desired IP address, gateway, and DNS servers.

How can you find the gateway IP in Ubuntu?

You can find the gateway IP by running the 'ip r' command, which will show the default route and the corresponding gateway IP address.

What is the significance of the 'gateway' parameter in network configuration?

The 'gateway' parameter specifies the default gateway, which is the IP address of the device that routes traffic from the local network to the outside world, such as the internet.

What is the difference between the network configuration commands used in Ubuntu 20 and Ubuntu 22?

In Ubuntu 20 and earlier versions, the 'gateway4' command is used to set the default gateway, while in Ubuntu 22, the 'routes' command is used to define the default gateway.