Linux Network Management

Table of contents

1. Ifupdown
2. Network Manager
3. Systemd-networkd
4. Netplan
5. Netifd

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Ifupdown

• After the driver successfully registers the net interface with the kernel, the ifupdown tool performs bring up and configures the interface.
• ifupdown reads configuration information from the /etc/network/interfaces file.
• Current Ubuntu distributions no longer use this model.
• Examples

# static IP
iface eth0 inet static
    address 192.168.0.111
    netmask 255.255.255.0
    gateway 192.168.0.1

# DHCP IP
iface eth0 inet dhcp

# Wi-Fi interface
iface wlan0 inet dhcp
    wireless-essid myessid
    wireless-key 123456789e

• For wireless interfaces or virtual interfaces, before configuring layer 3 through DHCP or static address, you need to create a link connection for layer 2. ifupdown provides a hook mechanism for users to create link connections.
• Hooks for ifupdown before bring up are located at: /etc/network/if-pre-up.d

# ls /etc/network/if-pre-up.d
bridge : Configure software bridge interface
wireless-tools: Configure wireless interface using iwconfig tool
wpasupplicant : Configure Wi-Fi interface in station mode

• For more information about Wi-Fi interface and virtual interface operations, see Linux Wi-Fi Driver and Linux Virtual Interface
• Reference: https://cumulusnetworks.github.io/ifupdown2/ifupdown2/userguide.html

Network Manager

• Network Manager is the default network management tool for Ubuntu desktop and server distributions from Ubuntu 15.04 to 20.04
• Supports connection types: ethernet, wireless, Mobile broadband, VPN, DSL
• Reference Network Manager

  Systemd-networkd

Netplan

Netifd