diff --git a/config/environments/ovb-common.yml b/config/environments/ovb-common.yml
index c424db866..704623c2b 100644
--- a/config/environments/ovb-common.yml
+++ b/config/environments/ovb-common.yml
@@ -13,7 +13,6 @@ undercloud_dhcp_start: 192.168.24.5
 undercloud_dhcp_end: 192.168.24.24
 undercloud_inspection_iprange: 192.168.24.25,192.168.24.39
 undercloud_external_network_cidr: 10.0.0.0/24
-undercloud_undercloud_nameservers: "{{ overcloud_dns_servers }}"
 
 # template copies
 undercloud_instackenv_template: "{{ local_working_dir }}/instackenv.json"
@@ -52,6 +51,9 @@ network_environment_args:
     [{'start': '{{ undercloud_external_network_cidr|nthhost(10) }}',
     'end': '{{ undercloud_external_network_cidr|nthhost(50) }}'}]
   NeutronExternalNetworkBridge: ""
+  ControlPlaneSubnetCidr: "{{ undercloud_network_cidr|ipaddr('prefix') }}"
+  ControlPlaneDefaultRoute: "{{ undercloud_network_cidr|nthhost(1) }}"
+  EC2MetadataIp: "{{ undercloud_network_cidr|nthhost(1) }}"
   ExternalInterfaceDefaultRoute: "{{ undercloud_external_network_cidr|nthhost(1) }}"
   InternalApiNetCidr: 172.20.0.0/24
   InternalApiAllocationPools: [{"start": "172.20.0.10", "end": "172.20.0.250"}]
@@ -61,6 +63,7 @@ network_environment_args:
   StorageMgmtAllocationPools: [{"start": "172.19.0.10", "end": "172.19.0.250"}]
   TenantNetCidr: 172.16.0.0/24
   TenantAllocationPools: [{"start": "172.16.0.10", "end": "172.16.0.250"}]
+  DnsServers: "{{ overcloud_dns_servers }}"
   PublicVirtualFixedIPs: [{"ip_address": "{{ undercloud_external_network_cidr|nthhost(5) }}"}]
   NeutronGlobalPhysnetMtu: 1350
   BondInterfaceOvsOptions: bond_mode=balance-slb
diff --git a/roles/overcloud-deploy/files/hardware_environments/virt/network_configs/single_nic_vlans_ipv4/single_nic_vlans_ipv4.yml b/roles/overcloud-deploy/files/hardware_environments/virt/network_configs/single_nic_vlans_ipv4/single_nic_vlans_ipv4.yml
index 9441b359a..6ecebe949 100644
--- a/roles/overcloud-deploy/files/hardware_environments/virt/network_configs/single_nic_vlans_ipv4/single_nic_vlans_ipv4.yml
+++ b/roles/overcloud-deploy/files/hardware_environments/virt/network_configs/single_nic_vlans_ipv4/single_nic_vlans_ipv4.yml
@@ -3,6 +3,8 @@
 # /home/stack/undercloud.conf for key local_ip
 # # EC2MetadataIp: "local_ip"
 #
+# #ControlPlaneSubnetCidr: key name must match the keyname found in
+# #/usr/share/openstack-tripleo-heat-templates/network/config/$type/node.yaml
 
 parameter_defaults:
   InternalApiNetCidr: 172.16.20.0/24
@@ -15,5 +17,7 @@ parameter_defaults:
   ExternalAllocationPools: [{'start': '172.16.23.110', 'end': '172.16.23.150'}]
   ExternalInterfaceDefaultRoute: 172.16.23.1
   NeutronExternalNetworkBridge: "''"
+  ControlPlaneSubnetCidr: "24"
+  ControlPlaneDefaultRoute: 192.0.2.1
   EC2MetadataIp: 192.0.2.1
   DnsServers: ["192.168.23.1", "8.8.8.8"]
diff --git a/roles/overcloud-deploy/files/hardware_environments/virt/network_configs/single_nic_vlans_ipv6/single_nic_vlans_ipv6.yml b/roles/overcloud-deploy/files/hardware_environments/virt/network_configs/single_nic_vlans_ipv6/single_nic_vlans_ipv6.yml
index 896c82b2f..fc2ff7307 100644
--- a/roles/overcloud-deploy/files/hardware_environments/virt/network_configs/single_nic_vlans_ipv6/single_nic_vlans_ipv6.yml
+++ b/roles/overcloud-deploy/files/hardware_environments/virt/network_configs/single_nic_vlans_ipv6/single_nic_vlans_ipv6.yml
@@ -32,5 +32,7 @@ parameters:
 
 parameter_defaults:
     DnsServers: ["192.168.122.1"]  # Customize for your env
+    ControlPlaneSubnetCidr: "24"
     EC2MetadataIp: 192.0.2.1  # Default for virt-env, customize if need be
+    ControlPlaneDefaultRoute: 192.0.2.1  # Default for virt-env, customize if need be
     ExternalInterfaceDefaultRoute: 2001:db8:fd00:1000:dead:beef:cafe:f00
diff --git a/roles/overcloud-prep-config/defaults/main.yml b/roles/overcloud-prep-config/defaults/main.yml
index d4741130a..973b19276 100644
--- a/roles/overcloud-prep-config/defaults/main.yml
+++ b/roles/overcloud-prep-config/defaults/main.yml
@@ -19,6 +19,8 @@ network_environment_args:
     [{'start': '{{ undercloud_external_network_cidr|nthhost(4) }}',
     'end': '{{ undercloud_external_network_cidr|nthhost(250) }}'}]
   NeutronExternalNetworkBridge: ""
+  ControlPlaneSubnetCidr: "{{ undercloud_network_cidr|ipaddr('prefix') }}"
+  ControlPlaneDefaultRoute: "{{ undercloud_network_cidr|nthhost(1) }}"
   EC2MetadataIp: "{{ undercloud_network_cidr|nthhost(1) }}"
   DnsServers: "{{ overcloud_dns_servers }}"