Initial dynamic eth0 configuration

src/freedombone-utils-network

     if [[ $INSTALLING_ON_BBB == "yes" ]]; then
         return
     fi
-    if [ ! $LOCAL_NETWORK_STATIC_IP_ADDRESS ]; then
-        return
-    fi
 
     echo '# This file describes the network interfaces available on your system' > /etc/network/interfaces
     echo '# and how to activate them. For more information, see interfaces(5).' >> /etc/network/interfaces
     echo 'source /etc/network/interfaces.d/*' >> /etc/network/interfaces
 
+    if [ ! $LOCAL_NETWORK_STATIC_IP_ADDRESS ]; then
+
+        { echo 'auto eth0';
+          echo 'iface eth0 inet dhcp'; } > /etc/network/interfaces.d/dynamic
+
+        if [ -f /etc/network/interfaces.d/static ]; then
+            rm /etc/network/interfaces.d/static
+        fi
+
+        mark_completed "${FUNCNAME[0]}"
+        return
+    fi
+
     { echo 'auto eth0';
       echo 'iface eth0 inet static';
       echo "    address $LOCAL_NETWORK_STATIC_IP_ADDRESS";
       echo '    netmask 255.255.255.0';
       echo "    gateway $ROUTER_IP_ADDRESS"; } > /etc/network/interfaces.d/static
 
-    mark_completed "${FUNCNAME[0]}"
+    if [ -f /etc/network/interfaces.d/dynamic ]; then
+        rm /etc/network/interfaces.d/dynamic
+    fi
 }
 
 function get_external_ipv4_address {