upstart-local-bridge

upstart-local-bridge

The upstart-local-bridge command is part of the Upstart system, now replaced by systemd in most modern Linux distributions. It's designed to configure and activate a network bridge specifically intended for local virtualization or containerization environments. The command is typically executed during the system's boot sequence by Upstart jobs. It simplifies the setup of a bridge interface, allowing virtual machines or containers to communicate with each other and potentially with the host system. The bridge device provides a virtual network switch, allowing the virtualized guests to connect as if they were on the same physical network. This command is not typically run manually by end-users, as its functionality is automated by Upstart at boot time. Its primary function is to ensure the bridge device is properly configured and active before virtual machines or containers attempt to use it. Using this command will often require root privileges to modify the network interfaces.

This command is specific to systems using Upstart. It's not applicable to systems using systemd. The configuration and creation of the local bridge are handled by other files, typically located in /etc/network/interfaces, or within Upstart job definition files.

The actual bridge configuration is often specified in /etc/network/interfaces. This file defines the bridge device (e.g., br0), assigned IP addresses, and attached network interfaces (e.g., eth0). The upstart-local-bridge job typically invokes commands like ifup br0 based on this configuration.

upstart-local-bridge was developed as part of the Upstart init system to manage system services and network configurations. It was commonly used in Ubuntu and other distributions that employed Upstart prior to the adoption of systemd. Its purpose was to simplify the network bridge configuration process during boot, particularly in environments where virtualization or containerization was prevalent. With the transition to systemd, similar functionality is now typically managed through network configuration files and systemd services.

brctl(8), ifconfig(8), ip(8)