CAN Interfaces

Linux provides CAN driver for physical available CAN controller and for virtual created CAN adapter so called vcan.

Physical CAN Interface

Physical can interfaces depends on hardware and driver support. To check if physical can interfaces are available do:

ifconfig -a | grep can

Output should be similar to following:

can0      Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
can1      Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00

To initialize an interface, do the following:

ip link set can0 type can bitrate 125000
ip link set up can0

It is then possible to send and receive data with:

cansend can0 1FFFFFFF#112233445D556677
candump can0

Virtual CAN Interface - vcan

To bring up virtual can interface the kernel module vcan is required. Load vcan module:

modprobe vcan

And controls whether the module is loaded successfully:

lsmod | grep vcan

Output should be similar to following:

vcan                   16384  0

Now a virtual can interface vcan0 can be created:

ip link add dev vcan0 type vcan
ip link set vcan0 mtu 16
ip link set up vcan0

To bring up CAN FD interface mtu size must increased to 72:

ip link add dev vcan0 type vcan
ip link set vcan0 mtu 72
ip link set up vcan0

And again control new created virtual can interface:

ifconfig vcan0

Output should be similar to following:

vcan0     Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
          UP RUNNING NOARP  MTU:16  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

From this point the virtual can interface vcan0 can be used e.g. for SocketCAN.


SocketCAN is used to tunnel CAN data over TCP/IP (e.g. ethernet). For linux based system, Cannelloni and socketcand are examples for user space tool which use SocketCAN.

Bind virtual can adapter vcan0 to any counterpart:

cannelloni -I vcan0 -R <remote ip> -r <remote port> -l <local port>

For non blocking console append a & in the command above.

Cannelloni Example

cannelloni example

In this example you see Machine 1 with a physical CAN-Interface (can0) and Machine 2 with a virtual CAN-Interface (vcan0). With cannelloni its now possible to link the two CAN-Interfaces together via the TCP/IP stack (UDP and SCTP). This makes it possible to read and write the physical CAN from Machine 2 as if it were directly connected to Machine 2. This is useful if you want to process the CAN-data on an external Machine.

Example use of SocketCAN between two machines.





Local cannelloni port




cannelloni -I can0 -R -r 2000 -l 2000


cannelloni -I vcan0 -R -r 2000 -l 2000

Now you can test the functionallity with the following commands.


candump can0


cansend vcan0 1FFFFFFF#112233445D556677

You should now see the data on can0.

External Physical CAN Interface

Ensure that any can participant is on can bus. For communication verification a can PC interface is recommendend. Check also that physical bus is proper terminated with 120 Ohm impedance.


can-utils provides severals tools to e.g. interact and monitor general can interfaces.

To send can frames to vcan0 command cansend can be used:

cansend <device> <can_frame>
# example
cansend vcan0 5A2#11.2233.445D556677.66

To dump can frames on a can interface use command candump:

candump <device>
# example
candump vcan0