CORD-433 Add virtual fabric to CiaB

Change-Id: I8fbea8c85f309a4c226951e0cde96a9b7394d6eb
diff --git a/ansible/roles/spineswitch/templates/spinebr.cfg.j2 b/ansible/roles/spineswitch/templates/spinebr.cfg.j2
new file mode 100644
index 0000000..4f0ebe4
--- /dev/null
+++ b/ansible/roles/spineswitch/templates/spinebr.cfg.j2
@@ -0,0 +1,7 @@
+auto spinebr
+iface spinebr inet static
+    address {{ net_prefix }}.253
+    network {{ net_prefix }}.0
+    netmask 255.255.255.0
+    broadcast {{ net_prefix }}.255
+    bridge_ports eth2 eth3