diff --git a/roles/compute-node/vars/main.yml b/roles/compute-node/vars/main.yml
index 62c9f19..01323a2 100644
--- a/roles/compute-node/vars/main.yml
+++ b/roles/compute-node/vars/main.yml
@@ -5,11 +5,15 @@
     interfaces:
         fabric: "{{ fabric_iface | default('fabric') }}"
         management: "{{ management_iface | default('mgmtbr') }}"
-        external: "{{ external_iface | default('') }}"
+        external: "{{ external_iface | default(None) }}"
+        file: "{{ iface_file | default('/etc/network/interfaces') }}"
     addresses:
         fabric: "{{ fabric_ip | mandatory }}"
         management: "{{ management_ip | default('dhcp') }}"
         external: "{{ external_ip | default('manual') }}"
     gateway:
-        external: "{{ external_gw | default('') }}"
-        management: "{{ management_gw | default('') }}"
+        external: "{{ external_gw | default(omit) }}"
+        management: "{{ management_gw | default('omit') }}"
+    broadcast:
+        external: "{{ external_bc | default(omit) }}"
+        management: "{{ management_bc | default('omit') }}"