nova/doc/v3/api_samples/server-ips/server-ips-network-resp.json

{
    "private": [
        {
            "addr": "192.168.0.3",
            "OS-EXT-IPS-MAC:mac_addr": "aa:bb:cc:dd:ee:ff",
            "OS-EXT-IPS:type": "fixed",
            "version": 4
        }
    ]
}