title: Cannot retrieve data from data store /restconf/config/opendaylight-inventory:nodes/ REST API
body: <p>I am using Opendaylight Carbon (also tried Oxygen) with Mininet. I created a small network which conects to the remote ODL Controller using OpenFlow 1.3 using Virtual machines (Ubuntu 18.04) on the same subnet and the mininet hosts can ping each other as expected.</p>
  <p>When connecting to the controller using a browser, I can login with default credentials and view the topoogy and Nodes using a web UI. Yang shows various properties of which very few gives a response from the controller.</p>
  <p>Problem: When sending the GET request: http://ip_address:8181/restconf/config/opendaylight-inventory:nodes/ I get an error message:</p>
  <p>&quot;Request could not be completed because the relevant data model content does not exist&quot;</p>
  <p>Note: I also get this error message on the switch when trying to view the flow table:
  mininet&gt; sh ovs-ofctl dump-flows s1
  2021-04-07T01:02:40Z|00001|vconn|WARN|unix:/var/run/openvswitch/s1.mgmt: version negotiation failed (we support version 0x01, peer supports version 0x04)
  ovs-ofctl: s1: failed to connect to socket (Broken pipe)</p>
  <p>However, I am getting this message with both ODL and RYU, so I am not sure if they are related.</p>
  <p>I need this to work in order to write a Python program to clear flow tables.</p>
  <p>Any advice will be appreciated.</p>