$json='
{
    "servers": [
        {
            "addresses": {
                "addr": [
                    {
                        "addr": "113.55.212.113",
                        "OS-EXT-IPS-MAC:mac_addr": "aa:bb:cc:dd:ee:ff",
                        "OS-EXT-IPS:type": "fixed",
                        "version": 4
                    }
                ]
            },
            "created": "2013-08-15T12:04:04Z",
            "flavor": {
                "id": "1",
                "links": [
                    {
                        "href": "http://openstack.example.com/flavors/1",
                        "rel": "bookmark"
                    }
                ]
            },
            "hostId": "117535ce0eda7ee02ebffe2c976173629385481ae3f2bded5e14a66b",
            "id": "ae114799-9164-48f5-a036-6ef9310acbc4",
            "image": {
                "id": "70a599e0-31e7-49b7-b260-868f441e862b",
                "links": [
                    {
                        "href": "http://openstack.example.com/images/70a599e0-31e7-49b7-b260-868f441e862b",
                        "rel": "bookmark"
                    }
                ]
            },
            "key_name": null,
            "links": [
                {
                    "href": "http://openstack.example.com/v2.1/servers/ae114799-9164-48f5-a036-6ef9310acbc4",
                    "rel": "self"
                },
                {
                    "href": "http://openstack.example.com/servers/ae114799-9164-48f5-a036-6ef9310acbc4",
                    "rel": "bookmark"
                }
            ],
            "metadata": {
                "My Server Name": "Tendaji"
            },
            "name": "Tendaji"
            "ipv4addr": "113.55.212.113"
        },
        {
            "addresses": {
                "addr": [
                    {
                        "addr": "143.179.56.126",
                        "OS-EXT-IPS-MAC:mac_addr": "aa:bb:cc:dd:ee:ff",
                        "OS-EXT-IPS:type": "fixed",
                        "version": 4
                    }
                ]
            },
            "created": "2013-08-15T12:04:04Z",
            "flavor": {
                "id": "1",
                "links": [
                    {
                        "href": "http://openstack.example.com/flavors/1",
                        "rel": "bookmark"
                    }
                ]
            },
            "hostId": "117535ce0eda7ee02ebffe2c976173629385481ae3f2bded5e14a66b",
            "id": "ae114799-9164-48f5-a036-6ef9310acbc4",
            "image": {
                "id": "70a599e0-31e7-49b7-b260-868f441e862b",
                "links": [
                    {
                        "href": "http://openstack.example.com/images/70a599e0-31e7-49b7-b260-868f441e862b",
                        "rel": "bookmark"
                    }
                ]
            },
            "key_name": null,
            "links": [
                {
                    "href": "http://openstack.example.com/v2.1/servers/ae114799-9164-48f5-a036-6ef9310acbc4",
                    "rel": "self"
                },
                {
                    "href": "http://openstack.example.com/servers/ae114799-9164-48f5-a036-6ef9310acbc4",
                    "rel": "bookmark"
                }
            ],
            "metadata": {
                "My Server Name": "Aboubacar"
            },
            "name": "Aboubacar"
            "ipv4addr": "143.179.56.126"
        }
    ]
}'

[System.Reflection.Assembly]::LoadWithPartialName("System.Web.Extensions")
$ser = New-Object System.Web.Script.Serialization.JavaScriptSerializer
$jsonObj = $ser.DeserializeObject($json)

$jsonObj.servers | Where-Object {$_.name -EQ 'Tendaji'} | `
  select-object { $_.ipv4addr }