Comment 0 for bug 1918914

After DHCP was turned on and off again on our network, new instances where not reachable. We found that they still tried to get their network config via DHCP after that.

We run Openstack Victoria installed with Openstack Kolla with OVN networking enabled. Also force_config_drive is set to true.

Steps to reproduce:

  openstack network create test
  openstack subnet create --no-dhcp --subnet-range 192.168.0.0/24 --network test test
  openstack router create test
  openstack router set test --external-gateway public
  openstack router add subnet test test

  openstack server create --network test --image e83d66e7-776a-4b59-a583-97dfcc5799f6 --flavor s3.small --key-name noudssh test-1

Network metadata:

{
   "links" : [
      {
         "ethernet_mac_address" : "fa:16:3e:b1:f6:ee",
         "id" : "tap7608d5b5-bd",
         "mtu" : 8942,
         "type" : "ovs",
         "vif_id" : "7608d5b5-bdc5-4215-a39c-acd8fa1318c2"
      }
   ],
   "networks" : [
      {
         "id" : "network0",
         "ip_address" : "192.168.0.237",
         "link" : "tap7608d5b5-bd",
         "netmask" : "255.255.255.0",
         "network_id" : "66a6378c-3e2d-4814-9412-4a784a81e516",
         "routes" : [
            {
               "gateway" : "192.168.0.1",
               "netmask" : "0.0.0.0",
               "network" : "0.0.0.0"
            }
         ],
         "services" : [],
         "type" : "ipv4"
      }
   ],
   "services" : []
}

Toggle DHCP and create new server:

  openstack subnet set --dhcp test
  openstack subnet set --no-dhcp test
  openstack server create --network test --image e83d66e7-776a-4b59-a583-97dfcc5799f6 --flavor s3.small --key-name noudssh test-2

Network metadata:

{
   "links" : [
      {
         "type" : "ovs",
         "id" : "tapee8f020a-1f",
         "vif_id" : "ee8f020a-1f2e-4db3-aab5-f6387fb45ba6",
         "ethernet_mac_address" : "fa:16:3e:94:05:35",
         "mtu" : 8942
      }
   ],
   "services" : [],
   "networks" : [
      {
         "network_id" : "66a6378c-3e2d-4814-9412-4a784a81e516",
         "link" : "tapee8f020a-1f",
         "type" : "ipv4_dhcp",
         "id" : "network0"
      }
   ]
}

As DHCP is now off, this instance stays unreachable.

I tried the same in a cluster with OVN disabled and that worked without any problem. So this seems to be OVN related.