Assuming that DHCP Server is running in the network and the problem is not receiving Offers for the DHCP Server.

My experience is the same as your, but in the Fedora 12.

Apparently, the packets of discover and request are sniffed in wireshark without a offer, but some reason what i don't know, those packets discover and request don't are transmited in the air. What explains no offer packets.

I restart the network service and after this the offers are receiving. In other words, after restart the network service the packets is transmited on the air !!!

Sorry for my english.


Leonardo Gomes.


De: sundar mahadevan <sundarmahadevan82@gmail.com>
Para: madwifi-users@lists.sourceforge.net
Enviadas: Quinta-feira, 10 de Junho de 2010 20:45:14
Assunto: [Madwifi-users] DHCPDISCOVER on ath0 to 255.255.255.255 port 67 interval

Hi All,
Greetings. I am on Oracle Enterprise Linux (OEL 5.5 x86_64) same as Redhat 5.5. I must use OEL5.5 because of my software installation requirements. My wlan card detects my network but its just not getting ip from my router assigned. I use WEP now. Earlier I had WPA since it more secure and it was the same issue, No DHCP offers. Then i installed madwifi but still the same issue. I have spent more than 20 hours trying to get wifi working but no luck. Your help is highly appreciated.

[root@suma1 /etc/sysconfig/network-scripts]$modprobe ath_pci
[root@suma1 /etc/sysconfig/network-scripts]$dhclient ath0
Internet Systems Consortium DHCP Client V3.0.5-RedHat
Copyright 2004-2006 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

Listening on LPF/ath0/90:4c:e5:56:ce:14
Sending on   LPF/ath0/90:4c:e5:56:ce:14
Sending on   Socket/fallback
DHCPDISCOVER on ath0 to 255.255.255.255 port 67 interval 6
DHCPDISCOVER on ath0 to 255.255.255.255 port 67 interval 13
DHCPDISCOVER on ath0 to 255.255.255.255 port 67 interval 13
DHCPDISCOVER on ath0 to 255.255.255.255 port 67 interval 10
DHCPDISCOVER on ath0 to 255.255.255.255 port 67 interval 19
No DHCPOFFERS received.
No working leases in persistent database - sleeping.
[root@suma1 /etc/sysconfig/network-scripts]$


[root@suma1 ~]$uname -a
Linux suma1 2.6.18-194.el5 #1 SMP Mon Mar 29 22:10:29 EDT 2010 x86_64 x86_64 x86_64 GNU/Linux

[root@suma1 ~]$ifconfig
ath0      Link encap:Ethernet  HWaddr 90:4C:E5:56:CE:14 
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)


[root@suma1 ~]$ifup wlan0
ath9k device wlan0 does not seem to be present, delaying initialization.

my router details are below:

[root@suma1 ~]$iwlist ath0 scan
ath0      Scan completed :
          Cell 01 - Address: 00:17:3F:E1:BD:2D
                    Channel:9
                    Frequency:2.452 GHz (Channel 9)
                    Quality=70/70  Signal level=-33 dBm 
                    Encryption key:on
                    ESSID:"suma"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
                              12 Mb/s; 24 Mb/s; 36 Mb/s
                    Bit Rates:9 Mb/s; 18 Mb/s; 48 Mb/s; 54 Mb/s
                    Mode:Master
                    Extra:tsf=0000003aaecae7ea
                    Extra: Last beacon: 362ms ago
                    IE: Unknown: 000473756D61
                    IE: Unknown: 010882848B960C183048
                    IE: Unknown: 030109
                    IE: Unknown: 0706555320010B1B
                    IE: Unknown: 2A0100
                    IE: Unknown: 32041224606C

[root@suma1 /etc/sysconfig/network-scripts]$cat ifcfg-ath0
# Atheros Communications Inc. AR928X Wireless Network Adapter (PCI-Express)
DEVICE=ath0
BOOTPROTO=dhcp
ONBOOT=yes
HWADDR=90:4c:e5:56:ce:14
NETMASK=
DHCP_HOSTNAME=
IPADDR=
BONDING_OPTS=
DOMAIN=
MASTER=
TYPE=WIRELESS
ESSID=suma
CHANNEL=9
MODE=managed
SECURITYMODE=off
RATE=auto
USERCTL=no
IPV6INIT=no
PEERDNS=yes

[root@suma1 /etc/sysconfig/network-scripts]$cat keys-ath0
KEY=9192078562

(fake key displayed above)