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I'm having some problems bringing up my wireless card at boot time on my Red Hat Linux 9.0 box. After some investigation with the boot scripts, I noticed that it was having problems with the DHCP negotiations when the ifup wlan0 command is issued.

I then tested the command outside of the booting process and everytime the command is issued the first time, the dhclient fails to get any DHCP offers and returns with the message Unable to obtain a lease on first try. Exiting. and then exits.

If I then issue the same ifup command again a second time, it successfully receives a DHCP offer from the router and receives the needed IP address, and after this, the Internet connection on the box works fine. It is consistently doing this everytime. Why is it failing to obtain a lease the first time?

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Probably the init script is trying to get the IP before the network card module is up: anyway you can add the ifup wlan0 command to /etc/rc.local.

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I think it is loading the network card module before trying to get the IP (what I did was disabled the option to bring the card up on startup and checked an "lsmod" right after the box has completed booting into Linux and it shows the needed modules are present. The scripts wouldn't even get to the part of calling dhclient if the modules were not loaded). However, I'll give your suggestion a go - it seems like a nice workaround. – methon.dagger Jul 17 '10 at 5:17

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