🚀 go-pugleaf

In aus.computers.linux on Sat, 10 Dec 2011 12:04:55 +1100
Polly the Parrott <flatulantdingo@deadspam.com> wrote:
>
> Now, the connection indicator shows as connected for either (depending
> of course on which one I select to be active), and shows in case of
> the wireless the signal strength, but in actual fact cannot browse,
> get mail etc etc.
>
> Firefox & others come up with "no network connection" sort of error.
>
> Dual boot, no such issue with Windoze.
>
>  ifconfig shows all RX & TX as errors, and I can ping the router ok.
>


Hmm... if you can ping the router, packets are getting out.  But they
might just be getting as far as the router.

There are two possiblities - network and firewall.  

Quick test - turn off any firewall at all.  Try again.  If it all now
works your firewall setup is corrupt and you might need to find an
Ubuntu forum to work out how to fix that.

You might need to check it really *is* off,  so get to a terminal
session and do
  sudo iptables -L
you should see something like

hain 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

that is, everything as accept.  If not, then you have to get to that
point.

If your firewall is off and you still can't connect then it's network,
the first job is to check the simplest case, which is ethernet.  So
turn off wireless.

I know nothing about ubuntu, but presumably all the command line tools
work and show something intelligent so try getting to a terminal and
doing
   netstat -r -n

You should get something like
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window
irtt Iface
192.168.1.0     0.0.0.0         255.255.255.0   U         0 0 0 eth1
0.0.0.0         192.168.1.124   0.0.0.0         UG        0 0 0 eth1

see that last line?  The many 0's are the "default route" and that
line is telling me that all packets destined for the great wide world
will head out via 192.168.1.124 which is my router.  

Check what yours says.

Then  do the same on Windows.  (I think the output is the same on
Windows, don't have one of those either...)

If you don't have a default route in netstat then somethng's amiss
with your network connection.  You can test it by doing 

  route add default gw www.xxx.yyy.zzz
where www.xxx.yyy.zzz is the IP address of your router, in my example
I'd do
  route add default gw 192.168.1.124

Now try firefox or something.  If that works then that's the
problem... fixing it means looking at your network configuration.  I
presume you are using something like Network Manager?  Find your
network configuration icon or look for how you configure your network
and check that everything is as it should be.  At a rough guess you
want to make sure you are using DHCP for everything.

If you are, and it's still a gateway problem we run into the "Zebee
knows nothing about Ubuntu" and you might need to head over to an
Ubuntu forum.  Else you can try telling it to use your router as a
gateway and sort it like that.

Now... supposing you do have a default route and it's the right one,
but not passing packets.

That gets more annoying :)

It means that your router is objecting to something about linux and
not windows.  

Check if you are using the same IP address in both.  In windows on the
command line do 
  ipconfig
and in linux
  ifconfig

the out put is not quite identical from memory but the basics should
be easy to see.

If you aren't getting the same IP, why not....  If your network is set
for DHCP that means something in the router, look there.

If you are, and the route's the same, and there's nothing obviously
set in the router, then I fear it is something
busted in your Network Manager (or whatever Ubuntu uses).

It is possible you have a corrupted file.  I suppose before finding
a forum you could delete your ethernet and wireless information
from your network manager setup, reboot (to make sure it really is
all clear, I don't trust NetworkManager...) and re-create your
setup.  That should clear any corrupted file.


Zebee