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-   -   Can't connect to internet using wireless on Ubuntu 10.10 despite having a connection (

K.out 12-24-2010 02:31 PM

Can't connect to internet using wireless on Ubuntu 10.10 despite having a connection

I would like some help setting up using a wireless connection. I can connect using wired connection, and I have no trouble browsing. I have a strong wireless connection as well; however, when I try to browse I get a server not found error.

I have done a lot of research but I don't know if any answers really matched my situation.

I did download the necessary drivers. Before that, I didn't have a wireless connection.

I was able to connect on this pc before the install, and all other devices still connect using wireless. I have a linksys router.

The one thing that stands out at me is the ip address that it says the wireless connection is using. It says it is
I feel like that might be problematic because I'm pretty sure my router only accepts connections with values that are between and

Thank you for the help,

wpeckham 12-24-2010 03:41 PM

This sounds like a networking issue rather than a Linux issue.
Can you tell us what kind of internet connection you have (in a general way), what kind of wireless router you use, and how you have security (encryption) set for your wireless connections?
I have to wonder if you are getting a wireless link to the wrong device, can you check that?

K.out 12-24-2010 05:31 PM

Router: linksys wrt54g
Encryption: wpa2 personal
How would I check if it's connecting to the wrong device?
Also, I disabled ipv6.
In addition, there is now a neighboring network being detected but it is secured as well so I can't try it. I disconnected the wired connection and my router still has my Linux box listed in the dhcp table with the ip that was being used when I was connected by cable; even after refresh

markush 12-24-2010 05:59 PM

Hi K.out,

are you using DHCP in your network?

Please post the output of


maybe you'll need the sudo command to execute this in Ubuntu.

How (with which tools) did you configure your WPA2 personal encryption?


K.out 12-24-2010 07:29 PM

Yes, I am using DHCP; I think that was default.

The encryption is set up with the router as well, lynksys software.

I always see people ask to post the results of iwconfig and ifconfig. What is gained from these postings, or what are you looking for in the results? Is it safe to post these? For instance, is it safe to give out your mac address?

Thank you,

markush 12-25-2010 02:34 AM


Originally Posted by K.out (Post 4202419)
I always see people ask to post the results of iwconfig and ifconfig. What is gained from these postings, or what are you looking for in the results? Is it safe to post these? For instance, is it safe to give out your mac address?

Well, you're inside a network which uses NAT (Network Adress Translation) which means that your router has a public IP-adress (which you really should not post here) and on the other side of the router, where your computer resides, there are private IP-adresses used, mostly and similar. The ifconfig command shows you, amongst other things, the private IP-adress which is useless for someone who would compromise your system from the internetside. So it is safe to post your private IP-adress here.

For the MAC-adress it is slightly different. When it comes to wireless networks, you're router can refuse unknown MAC-adresses (if you've configured this feature). If someone wants to connect to your wireless network and sees your MAC-adress here at LQ, he/she might use so called MAC-spoofing in order to make his/her computer's wireless adapter pretend to have the same MAC-adress as your's. But this is more a theoretical problem. You may therefore change the MAC-adress in the output of ifconfig or iwconfig to xx.xx.xx.xx.xx.xx.

...or what are you looking for in the results?...
At iwconfig I look for Accesspoint, connected or not authenticated.
At ifconfig I look if you have an apropriate IP-configuration for your network and if there is no output at all, one can assume that the apropriate driver is missing.


K.out 12-25-2010 09:54 AM

Cool, thanks for the description. It's nice to actually learn about some of this stuff instead just having somebody fix it for me.

me@me-name:~$ iwconfig
lo no wireless extensions.

eth0 no wireless extensions.

wlan0 IEEE 802.11bg ESSID:"connection"
Mode:Ad-Hoc Frequency:2.412 GHz Cell: xx:xx:xx:xx:xx:xx
Tx-Power=20 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Power Management:off

me@me-name:~$ ifconfig
eth0 Link encap:Ethernet HWaddr xx:xx:xx:xx:xx:xx
RX packets:6079 errors:0 dropped:0 overruns:0 frame:0
TX packets:5650 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:5254777 (5.2 MB) TX bytes:790697 (790.6 KB)

lo Link encap:Local Loopback
inet addr: Mask:
RX packets:236 errors:0 dropped:0 overruns:0 frame:0
TX packets:236 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:17800 (17.8 KB) TX bytes:17800 (17.8 KB)

wlan0 Link encap:Ethernet HWaddr xx:xx:xx:xx:xx:xx
inet addr: Bcast: Mask:
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:22 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:4786 (4.7 KB)

Ok, here is the output of the iwconfig and ifconfig. I just replaced the mac addresses with x's. I don't know what CELL is, or what it is used for, but it was different than any mac address and I replaced it with x's as well. I entered the commands when I was only connected to wireless. I just used a wired connection to copy them here after the fact. I don't think that matters though... because it seems like a history of your connections?

Also, as I said before it seems strange that it would say that I am connected, but I don't have a router assigned IP; I have that strange IP.

Thanks again,

markush 12-25-2010 10:08 AM

This is at least a valid IP-configuration for a network with the SSID "connection".
Is this the name of your wireless lan?
But I'm missing some output in iwconfig.

What did you do in order to configure your wireless adapter for your wireless network?

could you please post the output of

cat /etc/resolv.conf
this is the adress of the nameserver and should also be configured via DHCP.


K.out 12-25-2010 08:49 PM

Yes, that is the ssid that of my network.
Also, what is a network?
I thought that I had a

That was the complete iwconfig output.

I don't know of doing anything to configure the wireless
Adapter aside from installing the broadcom b43 wireless
Driver. Is that what you mean?

The cat /etc/resolve.conf just says
# Generated by NetworkManager

markush 12-26-2010 02:59 AM

Well, what about the encryption? did you tell your computer which key to use? and if so, which tool did you use? Did you configure your computer to use DHCP?

And there is no entry for a nameserver in the resolv.conf, which means altogether you'r computer has got no valid IP-configuration via DHCP.

I'd assume that you are not connected to your network. Unfortunately I don't have any experience with Ubuntu, so I can't tell where to enter the key and how to restart wlan0.

Maybe you'd be better off to post this issue in an Ubuntu forum


...Also, what is a network?...
it's another notation for a network with networkadress (the lowest ip in a network is the network adress) and 24bit subnetmask (

...I thought that I had a
no, this is not a valid networkadress.



ssreddy555 12-26-2010 06:35 AM

Select TKIP
In the wireless router interface, select security option as WPA2, select Encryption Protocol as AES - CCMP (& not TKIP) & Authentication method as Pre Selection Key (PSK) & give ur password in PSK field.

Selection of AES protocol is important. Seems Linux cannot decrypt TKIP.

Let me know whether u are successful.

K.out 12-26-2010 09:22 AM

It is already set to wpa2 and aes. There is no option for ccmp; so, I can't select that. I don't have tkip selected, and the is no field labeled psk, but I am guessing that the field I entered the password in is the same thing.

K.out 12-28-2010 05:59 PM

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