Nope, no setting. It should *just work*. Something is amiss with your browser, just not sure what.
Is this a machine you control yourself or is it managed by an IT group?
Can you try copy/pasting the link into your browser address bar instead of clicking on it?
Is there another web browser on the machine you could attemp to use?
(It's worth noting that hte CM5 requirements state the minimum Firefox version is 11, but that shouldn't impact the NameNode UI page and this doesn't feel like a browser compatibility issue.)
Kevin , I do have a proxy settings . When i disabled that i am able to browse the name node UI . Is there any possibility of using the both .