SIOCSIFFLAGS: No such file or directory

When I am starting wlan0 it shows me the following error:

SIOCSIFFLAGS: No such file or directory

I should install firmware, How to determine which firmware do I need?

How to determine Wifi card driver name(or module name)?

One person tells me that I should install :iwl5000-firmware-8.24.2.12-1.elrepo.noarch.rpm package but is this package for me?

Please help...My OS is CentOS 5.

Also what is firmware for?

Thank you

Try lspci, lsusb or dmidecode to find out what make your wireless card is. Once you know that you should only be a Google search away from the correct drivers (or post here and we can help you further).

It's actually a lot easier than Xiol suggests. Most drivers that need firmware will write the name of the file, and in some cases the URL to a helpful webpage, directly to dmesg. So all you should have to do is insert your driver, run dmesg, and look at the last few lines of output -- the answer should be right there.