diff --git a/network.sh b/network.sh
index 2f64031..599f1f1 100644
--- a/network.sh
+++ b/network.sh
@@ -2,8 +2,8 @@
 set -eu
 
 : ${VM_NET_TAP:=''}
+: ${VM_NET_MAC:=''}
 : ${VM_NET_IP:='20.20.20.21'}
-: ${VM_NET_MAC:='00:11:32:2C:A7:85'}
 
 : ${DNSMASQ:='/usr/sbin/dnsmasq'}
 : ${DNSMASQ_OPTS:=''}
@@ -61,6 +61,16 @@ if [ ! -c /dev/net/tun ]; then
 fi
 
 [ ! -c /dev/net/tun ] && echo "Error: TUN network interface not available..." && exit 85
+[ ! -d "$IMG" ] && echo "Storage folder (${IMG}) not found!" && exit 86
+
+#If environment variabele not set fall back to file
+if [ -z "$VM_NET_MAC" ]; then
+  FILE="${IMG}/guest.mac"
+  if [ ! -f "$FILE" ]; then
+    echo "00:11:32:2C:A7:85" > "$FILE"
+  fi
+  VM_NET_MAC=$(cat "${FILE}")
+fi
 
 update-alternatives --set iptables /usr/sbin/iptables-legacy > /dev/null
 update-alternatives --set ip6tables /usr/sbin/ip6tables-legacy > /dev/null