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Old 04-23-2008, 03:55 PM   #1
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Registered: Sep 2005
Location: UK
Distribution: Scientific Linux
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Wireless router and works, signal strong, DHCP IP issued fine. No access to web

Hi all,

I am trying to get my wireless operating on my laptop at home. I know that the wireless works fine, as our sysadmin got it functioning at work.

So I plug in our new wireless broadband router into the (ntl) cable modem, and set up the firmware: DHCP on, security off (for the time being).

As root I run:

sbin/modprobe rt2400
/sbin/ifconfig ra0 up
/sbin/iwconfig ra0 essid lemonpie
/sbin/dhclient ra0

Internet Systems Consortium DHCP Client V3.0.1
Copyright 2004 Internet Systems Consortium.
All rights reserved.
For info, please visit

/sbin/dhclient-script: configuration for ra0 not found. Continuing with defaults.
/etc/sysconfig/network-scripts/network-functions: line 52: ra0: No such file ordirectory
Listening on LPF/ra0/00:10:dc:ea:b6:b0
Sending on LPF/ra0/00:10:dc:ea:b6:b0
Sending on Socket/fallback
DHCPDISCOVER on ra0 to port 67 interval 7
DHCPREQUEST on ra0 to port 67
/sbin/dhclient-script: configuration for ra0 not found. Continuing with defaults.
/etc/sysconfig/network-scripts/network-functions: line 52: ra0: No such file ordirectory
SIOCADDRT: File exists
bound to -- renewal in 33260 seconds.

Here's the output of ifconfig:

[root@localhost nick]# /sbin/ifconfig
eth0 Link encap:Ethernet HWaddr **edited out**
inet addr: Bcast: Mask:
inet6 addr: fe80::240:d0ff:fe43:e9c5/64 Scope:Link
RX packets:2590 errors:0 dropped:0 overruns:0 frame:0
TX packets:2723 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:2243660 (2.1 MiB) TX bytes:526991 (514.6 KiB)
Interrupt:10 Base address:0x8100

lo Link encap:Local Loopback
inet addr: Mask:
inet6 addr: ::1/128 Scope:Host
RX packets:1427 errors:0 dropped:0 overruns:0 frame:0
TX packets:1427 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1492891 (1.4 MiB) TX bytes:1492891 (1.4 MiB)

ra0 Link encap:Ethernet HWaddr 00:10C:EA:B6:B0
inet addr: Bcast: Mask:
inet6 addr: fe80::210:dcff:feea:b6b0/64 Scope:Link
RX packets:187 errors:0 dropped:0 overruns:0 frame:0
TX packets:3 errors:0 dropped:0 overruns:0 carrier:0
collisions:1 txqueuelen:1000
RX bytes:68677 (67.0 KiB) TX bytes:7176 (7.0 KiB)

To my (limited) understanding, it appears that the wireless interface is operational, and an IP number issued ok.

When I run kwifimanager, I see the correct network name, IP number as above, noted that encryption is off, registers a strong signal. When I look at the connection statistics, I see it change regularly with time, suggesting a real connection between laptop and router.

Here's the output of netstat:

[root@localhost nick]# netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface U 0 0 0 eth0 U 0 0 0 ra0 U 0 0 0 eth0 UG 0 0 0 eth0

And I can connect fine to the internet via the ethernet cable (connected to the modem via the wireless router).


When I disconnect the ethernet cable, I no longer have access to the internet. Can't ping anything, no browser connection, no ssh.

I've tried to search the existing answers on LQ (and google etc etc) but I can't find anything more to do at this stage. Please forgive the ignorance which clearly is preventing me from seeing the obvious!

Would appreciate any and all help.

Old 04-23-2008, 05:37 PM   #2
Registered: Dec 2005
Location: Oregon
Distribution: Debian Testing
Posts: 488

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Maybe try the whole process again without the Ethernet cable being plugged in. ifdown eth0 should kill the wired connection. Having a wired and wireless connection from the same computer to the same router can cause problems, at least in my experience.

Next post, let us know what Linux distribution you are using and which wireless card.
Old 04-23-2008, 06:51 PM   #3
Junior Hacker
Senior Member
Registered: Jan 2005
Location: North America
Distribution: Debian testing Mandriva Ubuntu
Posts: 2,687

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In my experience with kwifimanager, which was a long time ago, it can only connect to a hot spot after the information is written to /etc/network/interfaces file, which for me was only achieved by using knetwork-conf to link up as administrator first. I eventually decided to can kwifimanager as I was only using knetwork-conf.
Have you tried using kwifimanager as root? To do so issue this command as a user in a shell: kdesu kwifimanager
Old 04-24-2008, 03:26 AM   #4
LQ Newbie
Registered: Sep 2005
Location: UK
Distribution: Scientific Linux
Posts: 4

Original Poster
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Hi all,

Thanks very much for the suggestions!

I actually discovered the solution not long after posting (of course). It was as suggested by pentode: restarting without the eth0 connected solved the problem and wireless now works fine.

And, I think that what JH says is correct, too - as I've discovered that kwifimanager now only works when run as root from the command line.

Now to set up encryption....

Thanks again,


P.S. Just to fill in blanks, I'm running Scientific Linux 2.6.9 and the wireless card is a RaLink 2400 with driver: rt2400 1.2.2 BETA3 2005/07/310. And the router is a Linksys WRT54G

Last edited by nikos3.14; 04-24-2008 at 03:29 AM. Reason: Incorrect model number given on driver; added router model info


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