Comment 7 for bug 38140

With a new, updated Edgy install, I took the default /etc/network/interfaces and replaced it with the following:

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
    address 192.168.5.2
    netmask 255.255.255.0
    gateway 192.168.5.1

After doing so, I ran;
/etc/init.d/networking restart

However, 30 minutes later, my system was unreachable at that IP, having received a DHCP lease. Found that the dhclient3 process was still running after the restart.

As ubuntu's networking init script is little more than a front-end to ifup/ifdown, it becomes prone to bug 38410.