diff --git a/tests/init-core-openstack.sh b/tests/init-core-openstack.sh
index 02a445c4ce..d50e82b06b 100755
--- a/tests/init-core-openstack.sh
+++ b/tests/init-core-openstack.sh
@@ -12,6 +12,19 @@ function init_runonce {
 
     echo "Initialising OpenStack resources via init-runonce"
     tools/init-runonce &> /tmp/logs/ansible/init-runonce
+
+    echo "Setting address on the external network bridge"
+    if [[ $SCENARIO == "linuxbridge" ]]; then
+        # NOTE(yoctozepto): linuxbridge agent manages its bridges by itself
+        # hence, we need to find the current name of the external network bridge
+        devname=$(basename $(readlink /sys/class/net/${EXT_NET_SLAVE_DEVICE}/master))
+    else
+        devname=br-ex
+        # NOTE(yoctozepto): ovs virtual interfaces are down (not used) by default
+        # hence, we need to bring the external network bridge up
+        sudo ip link set ${devname} up
+    fi
+    sudo ip addr add ${EXT_NET_LOCAL_ADDR} dev ${devname}
 }
 
 
diff --git a/tests/pre.yml b/tests/pre.yml
index 504e650823..7dcf4b87c8 100644
--- a/tests/pre.yml
+++ b/tests/pre.yml
@@ -16,6 +16,8 @@
         managed_network_prefix: "{{ api_network_prefix }}"
         managed_network_prefix_length: "{{ api_network_prefix_length }}"
         managed_network_address_family: "{{ address_family }}"
+    # NOTE(yoctozepto): no addressing for neutron_external_interface in here
+    # because it is enslaved by a bridge
     - role: multi-node-vxlan-overlay
       vars:
         vxlan_interface_name: "{{ neutron_external_interface_name }}"
diff --git a/tests/run.yml b/tests/run.yml
index e9bdfece58..f5f4251fdf 100644
--- a/tests/run.yml
+++ b/tests/run.yml
@@ -356,6 +356,13 @@
             cmd: init-core-openstack.sh
             executable: /bin/bash
             chdir: "{{ kolla_ansible_src_dir }}"
+          environment:
+            EXT_NET_CIDR: "{{ neutron_external_network_prefix }}0/{{ neutron_external_network_prefix_length }}"
+            EXT_NET_RANGE: "start={{ neutron_external_network_prefix }}150,end={{ neutron_external_network_prefix }}199"
+            EXT_NET_GATEWAY: "{{ neutron_external_network_prefix }}1"
+            EXT_NET_LOCAL_ADDR: "{{ neutron_external_network_prefix }}1/{{ neutron_external_network_prefix_length }}"
+            EXT_NET_SLAVE_DEVICE: "{{ neutron_external_interface_name }}"
+            SCENARIO: "{{ scenario }}"
           when: openstack_core_tested or scenario in ['ironic', 'scenario_nfv', 'zun']
 
         - name: Run test-core-openstack.sh script
diff --git a/zuul.d/base.yaml b/zuul.d/base.yaml
index dc30e6ac44..563674edcd 100644
--- a/zuul.d/base.yaml
+++ b/zuul.d/base.yaml
@@ -32,6 +32,8 @@
       api_interface_name: vxlan0
       kolla_internal_vip_address: "192.0.2.10"
       address_family: 'ipv4'
+      neutron_external_network_prefix: "198.51.100."
+      neutron_external_network_prefix_length: "24"
       neutron_external_interface_name: vxlan1
       tls_enabled: false
     roles: