DHCPREQUEST not replied

Question

I have installed wpa_supplicant on Debian Squeeze so i can connect to my home and the school WiFi network. My home network is secured with WPA2 AES and I can connect to this network without any problems at all, I recieve an IP address immediately and the connection is stable. The school network is an open network without any security, I can connect to this network but I have problems recieving an IP address.

If i run wpa_cli status after activating the school network the following is printed on the screen:

ssid=school-network
pairwise_cipher=NONE
group_cipher=NONE
key_mgmt=NONE
wpa_state=COMPLETED

Then I read the syslog file and find this:

dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 12
dhclient: DHCPOFFER from 172.10.100.1
dhclient: DHCPREQUEST on wlan0 to 255.255.255.255 port 67
dhclient: DHCPREQUEST on wlan0 to 255.255.255.255 port 67
dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 6
dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 7
dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 11
dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 15
dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 9
dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 13
dhclient: No DHCPOFFERS received

Then after some time, between 1 - 15 minutes, this is printed.

dhclient: DHCPOFFER from 172.10.100.1
dhclient: DHCPREQUEST on wlan0 to 255.255.255.255 port 67
dhclient: DHCPACK from 172.10.100.1
dhclient: bound to 172.10.102.110 -- renewal in 36827 seconds.

And now the connections is established. Sometimes I recieve an IP address immediately, but most of the time I have to wait.

I do not know where to start debugging this problem?

Answer 1

Sounds like a timing problem. To debug, stop the running dhclient and start a new one in the foreground. You'll be able to see more than just what's reported in syslog.

# /etc/init.d/dhclient stop and then # dhclient -d

You should be able to see if your client is waiting for a better offer, ignores it or something like that.