Comment 16 for bug 293139

A possible workaround, as well as additional confirmation of the bug, is mentioned here: http://www.webtatic.com/blog/2009/03/workaround-so-networkmanager-runs-dhclient-hooks/

From the site:

"Sadly NetworkManager fails to call any hooks on dhcp renew, which is what my script needed. It only calls its hooks, which are located in /etc/NetworkManager/dispatcher.d/, when the interface is brought up or down.

I’ve made a modified dhclient-script, which when set as the dhclient script, will call the enter hooks, then call NetworkManager’s dhclient script, then call the exit hooks. This effectively gives the intended effect of allowing NetworkManager to run with the old dhcp hooks available."

He then attaches the following script.