root@odroid:~# ifconfig can0 down
root@odroid:~# ip link set can0 type can bitrate 125000 loopback on
root@odroid:~# ifconfig can0 up
root@odroid:~# ip -details link show can0
3: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc fq_codel state UNKNOWN mode DEFAULT group default qlen 10
    link/can  promiscuity 0 
    can <LOOPBACK,TRIPLE-SAMPLING> state ERROR-ACTIVE restart-ms 0 
          bitrate 125000 sample-point 0.850 
          tq 400 prop-seg 8 phase-seg1 8 phase-seg2 3 sjw 1
          mcp251x: tseg1 3..16 tseg2 2..8 sjw 1..4 brp 1..64 brp-inc 1
          clock 5000000numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
root@odroid:~#