diff --git a/scripts/vm/hypervisor/xenserver/cloud-prepare-upgrade.sh b/scripts/vm/hypervisor/xenserver/cloud-prepare-upgrade.sh
index d0eca3ed6dd..857fcd24f52 100755
--- a/scripts/vm/hypervisor/xenserver/cloud-prepare-upgrade.sh
+++ b/scripts/vm/hypervisor/xenserver/cloud-prepare-upgrade.sh
@@ -4,23 +4,31 @@
 #set -x
 
 # propagate VLANs to other host
-for networkname in $(xe network-list | grep "name-label ( RW): VLAN" | awk '{print $NF}');
-do 
-  network=$(xe network-list name-label=$networkname --minimal)
-  tagpif=$(xe pif-list  network-uuid=$network --minimal | cut -d, -f 1)
-  device=$(xe pif-param-get uuid=$tagpif param-name=device)
-  vlan=$(xe pif-param-get uuid=$tagpif param-name=VLAN)
+
+for vlan_networkname in $(xe network-list | grep "name-label ( RW): VLAN" | awk '{print $NF}');
+do
+  vlan_network=$(xe network-list name-label=$vlan_networkname --minimal)
+  this_tagged_pif=$(xe pif-list  network-uuid=$vlan_network --minimal | cut -d, -f 1)
+  if [ -x $this_tagged_pif ]; then
+    continue
+  fi
+  vlan=$(xe pif-param-get uuid=$this_tagged_pif param-name=VLAN)
+  this_host=$(xe pif-param-get uuid=$this_tagged_pif param-name=host-uuid)
+  this_device=$(xe pif-param-get uuid=$this_tagged_pif param-name=device)
+  untagged_pif=$(xe pif-list host-uuid=$this_host device=$this_device VLAN=-1 --minimal)
+  untagged_network=$(xe pif-param-get uuid=$untagged_pif param-name=network-uuid)
   for host in $(xe host-list | grep ^uuid | awk '{print $NF}')
   do
-    tagpif=$(xe pif-list network-uuid=$network host-uuid=$host --minimal)
+    tagpif=$(xe pif-list network-uuid=$vlan_network host-uuid=$host --minimal)
     if [ -z $tagpif ]; then
-      pif=$(xe pif-list host-uuid=$host device=$device VLAN=-1 --minimal)
-      xe vlan-create network-uuid=$network pif-uuid=$pif vlan=$vlan
+      pif=$(xe pif-list host-uuid=$host network_uuid=$untagged_network --minimal)
+      xe vlan-create network-uuid=$vlan_network pif-uuid=$pif vlan=$vlan
     fi
   done
 done
 
 
+
 # fake PV for PV VM
 
 fake_pv_driver() {
@@ -38,7 +46,6 @@ fake_pv_driver() {
   xe host-call-plugin host-uuid=$host plugin=vmops fn=preparemigration args:uuid=$vm
 }
 
-
 vms=$(xe vm-list is-control-domain=false| grep ^uuid | awk '{print $NF}')
 for vm in $vms
 do