Comment 5 for bug 38140

Bug 49801 has been marked as duplicate of this bug, hence I add the comment here:
49801 might actually be caused by the (erroneous) assumption of the if-up/down tools that their configuration file is immutable. If, e.g. the configuration file is adjusted to use static address assignement, after an IP address was allocated using DHCP during if-up, but before if-down is executed, the latter wont attempt to kill the dhcp client.