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Old 06-03-2005, 11:39 AM   #1
wmburke
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can't ping DNS


I have a dual boot w2k/Ubuntu laptop with a wireless card. Networking is fully functional on the the w2k side, but on the Ubuntu side, I can't get to the internet in any way, I can't even ping the DNS server.

DHCP is fully functional and I can ping any machine on this side of the router and the router itself.

Route shows:

Code:
Destination   Gateway       Genmask       Flags Metric Ref Use Iface
192.168.0.0   *             255.255.255.0 U     0       0   0  eth1
default       192.168.0.1   0.0.0.0       UG    0       0   0  eth1
This seems like I must be missing something obvious, but PLEASE tell me what it is...

Thanks,
Wayne
 
Old 06-03-2005, 04:23 PM   #2
Hangdog42
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It could be that the DNS is configured to not respond to pings.

I'm assuming that if you can ping computers on your LAN, you do have the card properly configured, but you might want to post the outputs of ifconfig and iwconfig if you're not sure.

If you think it is a DNS issue, try using your browser to access 64.179.4.149 (the IP address of Linuxquestions.org) If that works, but using the name www.linuxquestions.org doesn't then you do have a DNS issue and we can try a couple of things. However, if you can't get to LQ using the IP address then something else is wrong, like a firewall problem or card configuration.
 
Old 06-03-2005, 05:36 PM   #3
wmburke
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Well, I appreciate the thoughts, but I can ping the DNS from W2k side, and can't get to 64.179.4.149 from my browser, so I think DNS issues are ruled out. That leaves us with firewall or card configuration.

To complicate the issue even further, I have no problems connecting to my home wireless network, just to the one at work. The one at work services multiple wireless XP laptops every day, and also works with my W2k side, so I don't believe it's a network issue.

Ubuntu does not come standard with a firewall and I haven't installed one, although if there is a way to verify that I don't have one, I'm happy to do so.

As far as network firewall, there isn't one installed at work for their wireless network.

As far as card config, here is the iwconfig and ifconfig outputs:
Code:
wmburke@ubuntu:/usr/share/freemind$ iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

eth1      IEEE 802.11-DS  ESSID:"VOWIRELESS"  Nickname:"Prism  I"
          Mode:Managed  Frequency:2.412 GHz  Access Point: 00:13:C3:9B:87:40
          Bit Rate:11 Mb/s   Tx-Power=15 dBm
          Retry min limit:8   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality=48/92  Signal level=-51 dBm  Noise level=-141 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

sit0      no wireless extensions.

wmburke@ubuntu:/usr/share/freemind$ ifconfig
eth1      Link encap:Ethernet  HWaddr 00:06:25:17:53:D3
          inet addr:192.168.0.87  Bcast:192.168.0.255  Mask:255.255.255.0
          inet6 addr: fe80::206:25ff:fe17:53d3/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:405 errors:0 dropped:0 overruns:0 frame:0
          TX packets:52 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:89387 (87.2 KiB)  TX bytes:7422 (7.2 KiB)
          Interrupt:3 Base address:0x100

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:2371 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2371 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:618873 (604.3 KiB)  TX bytes:618873 (604.3 KiB)
The only other thing I can think of is that there is some compatibility issue with the wireless access point, except I can ping other machines through it and I can ping the gateway, so I'm not sure what that means.

Thanks for your help.

Wayne

Last edited by wmburke; 06-03-2005 at 06:05 PM.
 
Old 06-04-2005, 07:55 AM   #4
Hangdog42
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OK, from your route, iwconfig and ifconfig outputs it looks as if your card is configured correctly and has everything it needs to access the net. You can do a quick check of the firewall by running iptables -L in a console as root. At the moment, the only other thing I can think of is to have a look in your syslog and messages (both in /var/log) and see if anything is there relating to your wirless card.

Just out of curiosity, can you use a wired ethernet connection from Linux? If you can, it might be enlightening if you can access the net from the wired connection but not the wireless.

Quote:
I have no problems connecting to my home wireless network, just to the one at work. The one at work services multiple wireless XP laptops every day, and also works with my W2k side, so I don't believe it's a network issue.
OK, one issue this brings up is the security that your workplace has in place. It is highly likely that they have WEP or WAP encryption and are keeping the key a tightly held secret. If that is the case, it could be you simply don't have the right information to connect. Does your work IT support linux or are you off on an unapproved adventure?
 
Old 06-07-2005, 04:47 PM   #5
wmburke
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The laptop connects great through a wired connection, still not through wireless. There is no encryption on the wireless network at work. Although this is a side project for me, I am the IT guy also. In addition, my W2k side works fine on the wireless at the same place.

Today, I'm at a different location with the same company, and have exactly the same situation.

iptables -L shows
Code:
Chain INPUT (policy ACCEPT)
target        prot opt source                  destination

Chain FORWARD (policy ACCEPT)
target        prot opt source                  destination

Chain OUTPUT (policy ACCEPT)
target        prot opt source                  destination
I have seen several other people asking about this on several different forums, but have yet to see an answer to it. This seems to be quite an interesting dilemma.

Thank you for all of your help. I look forward to uncovering this solution.
 
Old 06-07-2005, 08:49 PM   #6
Hangdog42
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Dang. OK, from what you've posted so far the problem is NOT:

the card hardware
the card drivers
the laptop firewall
the card configuration
lack of an IP address
an incorrect gateway
the company wireless security
a nameserver problem

And since the wired connection works fine, there isn't a basic problem with TCP/IP on the laptop.


In other words, we've ruled out about 99.99% of what usually goes wrong. And to be honest, I'm stumped. So what follows are honest to goodness fishing questions, and I won't be even remotely offended if you seek other opinions....

Since the connection can be made under Windows, but not Linux, it might be worth exploring any differences in the way the two network settings are configured. Are both using DHCP? Do you know of any MAC address:IP pairing security that might be happening at the access point?


If you set up your firewall to log packets on the input and output chains, it might help figure out what is happening when you try to access the internet. A couple of rules like this:

iptables -A INPUT -i eth1 -j LOG --log-prefix "INPUT: "
iptables -A OUTPUT -i eth1 -j LOG --log-prefix "OUTPUT: "

This will fill up your /var/log/messages file pretty quickly, but if you run it for a bit it might tell you if packets are going out and returning (use iptables -F to flush out the rules and stop logging).

It also might be interesting if a program like ethereal can see the normal network chattter or be helpful in seeing what is happening to the packets.

You might want to force off your wired interface (ifconfig eth0 down will turn it off). Sometimes you see conflicts between wired and wireless connections.

Can you get the card running with a live distro like Knoppix? It might be somewhat revealing if Knoppix worked but Unbuntu didn't.

Is there another make of wireless card you could try in this laptop?

But like I said earlier, I'm stumped by this.
 
Old 06-08-2005, 12:23 PM   #7
wmburke
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You're gonna love this!

Inexplicably, it works today.

Yesterday, I was at a second location and couldn't get it to work wirelessly, but it did work wired.

Today, I'm back at the main location, I booted it up unexpectedly and voila! it suddenly tells me that I have new updates to install.

The only difference I can recognize is that previously I had not set up the nic, only the wireless card. Now both the nic and wireless card are configured AND active! That's a switch, huh?!? It works with the other active!

I'm going to do some tests to figure out when it works or doesn't and I'll let you know.

Thanks again for the help...

Wayne
 
Old 06-08-2005, 02:12 PM   #8
Hangdog42
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Maybe I'll see if I can check with NASA on the status of solar flares today.........It makes as much sense as anything else I can think of.
 
  


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