dynamic NIC block display

i3/i3blocks.conf

@@ -70,13 +70,13 @@ interval=30
 # If the instance is not specified, use the interface used for default route.
 # The address can be forced to IPv4 or IPv6 with -4 or -6 switches.
 [iface]
-instance=eth0
+#instance=eth0
 color=#00FF00
 interval=10
 separator=false
 
 [bandwidth]
-instance=eth0
+#instance=eth0
 interval=5
 
 # CPU usage