network may be identified by id or name.
POST /rhevm-api/hosts/2ab5e1da-b726-4274-bbf7-0a42b16a0fc3/nics/e8f02fdf-3d7b-4135-86e1-1bf185570cd8/attach HTTP/1.1
Content-type: application/xml
<action>
<network id="e657d631-657d-42bb-a536-73501a085d85"/>
</action>