can0

can0 is the common network interface name used by Linux's SocketCAN framework to represent a Controller Area Network (CAN) device on a host. SocketCAN exposes CAN buses as standard network interfaces, allowing applications to send and receive CAN frames using socket APIs.

A can0 interface is created when a CAN controller is connected and its driver is loaded. Real hardware such as MCP2515-based boards or USB-CAN adapters will appear as can0 (and may be can1, can2, etc., if multiple channels are present). There is also a virtual interface called vcan0, which is used for testing without a physical CAN bus.

To use the interface, it must be brought up and configured with a bitrate. Common steps involve commands like: ip link set can0 up type can bitrate 500000. The exact options depend on the kernel and driver, and CAN FD support may require additional parameters.

Applications access can0 via the socketCAN API, enabling programs to create PF_CAN sockets and exchange frames with standard CAN IDs and payloads. Developers often use the can-utils package for quick testing, with tools such as cansend, candump, and canplayer.

Naming generally reflects the first CAN interface discovered (can0); additional adapters appear as can1, can2, and so on. can0 thus serves as a bridge between CAN hardware and software, integrating CAN traffic into Linux network programming and system diagnostics.