[solved] udhcpc cannot obtain IP in WIFI

[Xianwen Chen]

Hi all,

I use a USB Realtek 8187B wireless adapter. I find that udhcpc cannot obtain IP. I have to use dhcpcd every time. Is it just me having this problem?

Thanks in advance.

[Juanito]

Using a dell dw1530 wireless card, I need to run udhcpc once, kill the process and run udhcpc again - it always works the second time.

[gerald_clark]

You could use the nodhcp boot optiion so you can run udhcpc at the proper time.

[Juanito]

Thanks, but in my case I'm not sure that would change anything (there was no problem with my previous hardware) - plus I need udhcpc running in case I use a wired connection.

[gerald_clark]

You can always run it in bootlocal.sh.

[Xianwen Chen]

Using a dell dw1530 wireless card, I need to run udhcpc once, kill the process and run udhcpc again - it always works the second time.

Hi Juanito,

Thank you. I tried to run udhcpc multiple times. However, I cannot obtain IP from DHCP server with udhcpc. I use a USB wireless adapter with Realtek 8187B chip.

[Juanito]

could you post the output you get when you try to run udhcpc - make sure there are no other instances of udhcpc running first

[Xianwen Chen]

could you post the output you get when you try to run udhcpc - make sure there are no other instances of udhcpc running first

Hi Juanito,

Thank you. I took Gerald Clark's advice. The option 'nodhcp' was added to the boot menu. No 'udhcpc' instance was running at system startup.

My landlord uses WPA to protect her WIFI. After I associated the USB wireless adapter to the WIFI, I tried both 'udhcpc' and 'udhcpc wlan0' twice. It always repeated reporting 'Sending discover...'. I waited several minutes for each trial.

The USB adapter is connected to one of the USB ports. The light did not blink when 'udhcpc' was trying to discover the DHCP server. That suggests that 'udhcpc' might not have sent signal through the adapter.

As usual, 'dhcpcd' obtained IP from the DHCP server instantly.

[tinypoodle]

After I associated the USB wireless adapter to the WIFI, I tried both 'udhcpc' and 'udhcpc wlan0' twice.

sudo udhcpc -i wlan0

[Juanito]

You need to use something like this:

Code: [Select]

$ sudo udhcpc -b -i wlan0 -x hostname:box -p /var/run/udhcpc.wlan0.pid

[Xianwen Chen]

The problem has been solved. Thank you Tinypoodle and Juanito.

[tinypoodle]

Just by

Code: [Select]

udhcpc --helpyou could see that you actually were trying to get a lease for eth0

[Xianwen Chen]

Just by

Code: [Select]

udhcpc --helpyou could see that you actually were trying to get a lease for eth0

Thank you tinypoodle.