I have a wireless device named wlan0, and, after editing /etc/sysconfig/network-scripts/ifcfg-wlan0 I use ifup wlan0 to start wireless networking.
However, this fails often, typically by dhcpd failing, with errors in /var/log/messages like:
wlan0: link is not ready send_packet: Network is down
This is in Fedora 11. These same parameters worked fine in FC8. And NetworkManager/Gnome connects fine.
Does anybody have any idea why NetworkManager can connect to networks that ifup cannot?