[
  {
    "ifindex": 4,
    "ifname": "e2",
    "flags": [
      "BROADCAST",
      "MULTICAST",
      "UP",
      "LOWER_UP"
    ],
    "mtu": 1500,
    "master": "br1",
    "state": "forwarding",
    "priority": 32,
    "cost": 100
  }
]