ifup will not get ip address

Ok, first, I’m a newbie to Linux.
Running on a windows ad network. Originally I had a reserved ip address in dhcp because it is needed to get to the internet for updates and rpms.
When I deleted the reservation in dhcp, to get a regular ip, did ifdown/up my box will not get a new ip address. Even a reboot didn’t work.
Only dhclient seems to grab the address. I finally switched to Network Manager, out of frustration and it works.
So, my question is: Why isn’t ifup working with dhcp but it works with static ip?
Thanks Joe C.

Most likely due to some misconfiguration, it works fine with ifup and DHCP here (and of course also with static IPs).

Check in Yast → network devices → network settings → overview → that you have an assignment for IP by DHC P and set to start at boot. Here are some pics (check the default dhcp pics #1 through #6): HowTo Configure a network card in Suse/openSUSE 10, 11 for LAN and Internet Access.