Rich Shepard | 26 Mar 20:35 2012

Laptop Connects to WAP, But Cannot Access 'Net

   This is a different situation, one I've not before encountered. On the
Sony Vaio (running -13.37/x86_64 with the 3.2.7 kernel), wicd-client shows a
connection to the local wireless access point and provides DNS servers in
/etc/resolv.conf, but will not load a Web page nor allow ping, traceroute,
or host commands. This happens at two different wifi hot spots.

   What might be missing when wicd connects to a WAP but the user cannot
reach a URL in a Web browser? With the wicd gui it's possible to disconnect
and reconnect to the local network but still not be able to do anything once
connected. I don't know enough about wireless networking to have any idea of
all the pieces. In my experience with other portables, if I could connect to
a WAP I could access the 'Net.

TIA,

Rich
Claudio Fontana | 26 Mar 20:47 2012
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Re: Laptop Connects to WAP, But Cannot Access 'Net

On Mon, Mar 26, 2012 at 8:35 PM, Rich Shepard <rshepard <at> appl-ecosys.com> wrote:
>  This is a different situation, one I've not before encountered. On the
> Sony Vaio (running -13.37/x86_64 with the 3.2.7 kernel), wicd-client shows a
> connection to the local wireless access point and provides DNS servers in
> /etc/resolv.conf, but will not load a Web page nor allow ping, traceroute,
> or host commands. This happens at two different wifi hot spots.
>
>  What might be missing when wicd connects to a WAP but the user cannot
> reach a URL in a Web browser? With the wicd gui it's possible to disconnect
> and reconnect to the local network but still not be able to do anything once
> connected. I don't know enough about wireless networking to have any idea of
> all the pieces. In my experience with other portables, if I could connect to
> a WAP I could access the 'Net.
>
> TIA,
>
> Rich

Hmm without any more information I would first check the firewall
rules for all involved interfaces, assuming that you checked that the
wpa authentication was successful, and that the internet connection is
up at the router, and that the other clients on the LAN (on cable
f.e.) can access the internet.

My 2c, ciao,

Claudio
Rich Shepard | 26 Mar 21:25 2012

Re: Laptop Connects to WAP, But Cannot Access 'Net

On Mon, 26 Mar 2012, Claudio Fontana wrote:

> Hmm without any more information I would first check the firewall rules
> for all involved interfaces, assuming that you checked that the wpa
> authentication was successful, and that the internet connection is up at
> the router, and that the other clients on the LAN (on cable f.e.) can
> access the internet.

Claudio,

   There's no firewall and no authentication; these public wifi hot spots are
unsecured so everyone can use them.

   I have no idea what's happening on their router since I've no access to
it.

Rich
Claudio Fontana | 26 Mar 22:03 2012
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Re: Laptop Connects to WAP, But Cannot Access 'Net

On Mon, Mar 26, 2012 at 9:25 PM, Rich Shepard <rshepard <at> appl-ecosys.com> wrote:
> On Mon, 26 Mar 2012, Claudio Fontana wrote:
>
>> Hmm without any more information I would first check the firewall rules
>> for all involved interfaces, assuming that you checked that the wpa
>> authentication was successful, and that the internet connection is up at
>> the router, and that the other clients on the LAN (on cable f.e.) can
>> access the internet.
>
>
> Claudio,
>
>  There's no firewall and no authentication; these public wifi hot spots are
> unsecured so everyone can use them.
>
>  I have no idea what's happening on their router since I've no access to
> it.

I see, I assumed a local setup  <at> home, did not get the public wifi part.

Anyway, one check to the firewall rules on the _client_, even just an
iptables -v -L ,
as well as the routing tables maybe could be something to look at.

Ciao,

Claudio
Rich Shepard | 26 Mar 22:12 2012

Re: Laptop Connects to WAP, But Cannot Access 'Net

On Mon, 26 Mar 2012, Claudio Fontana wrote:

> Anyway, one check to the firewall rules on the _client_, even just an
> iptables -v -L , as well as the routing tables maybe could be something to
> look at.

Claudio,

   It's a fresh installation; everything is at default values other than
/etc/host* and resolv.conf.

   My Dell is set up the same way and it has no problems connecting to wifi
hot spots when I'm traveling.

Thanks,

Rich
Bengt Richter | 26 Mar 21:18 2012
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Re: Laptop Connects to WAP, But Cannot Access 'Net

On 03/26/2012 11:35 AM Rich Shepard wrote:
>     This is a different situation, one I've not before encountered. On the
> Sony Vaio (running -13.37/x86_64 with the 3.2.7 kernel), wicd-client shows a
> connection to the local wireless access point and provides DNS servers in
> /etc/resolv.conf, but will not load a Web page nor allow ping, traceroute,
> or host commands. This happens at two different wifi hot spots.
>
>     What might be missing when wicd connects to a WAP but the user cannot
> reach a URL in a Web browser? With the wicd gui it's possible to disconnect
> and reconnect to the local network but still not be able to do anything once
> connected. I don't know enough about wireless networking to have any idea of
> all the pieces. In my experience with other portables, if I could connect to
> a WAP I could access the 'Net.
>
> TIA,
>
> Rich
Could there be an http-only page demanding you agree to terms of use before
they open other ports? Have you tried to access with a browser first?

I have experienced apparent inaccessibility on the road just to find out
that ports are not opened until you click an agreement to terms-of-use in an http
page presented by a proxy I think, and I hadn't seen it because I had tried to
get email first, which was a port that was shut off.
Rich Shepard | 26 Mar 21:29 2012

Re: Laptop Connects to WAP, But Cannot Access 'Net

On Mon, 26 Mar 2012, Bengt Richter wrote:

> Could there be an http-only page demanding you agree to terms of use
> before they open other ports? Have you tried to access with a browser
> first?

Bengt,

   At the place I tried yesterday, yet. But, when I entered the URL nothing
happened; firefox just sat there.

   I did not try to reach their web site before establishing a connection to
their WAP.

> I have experienced apparent inaccessibility on the road just to find out
> that ports are not opened until you click an agreement to terms-of-use in
> an http page presented by a proxy I think, and I hadn't seen it because I
> had tried to get email first, which was a port that was shut off.

   I've seen this in a couple of the hotels where I stay on business trips,
and when I cannot ssh to my network I remember that I need to access their
web site first. But, I was not able to do that yesterday.

   The other location is a coffee shop with unsecured wife access; no
validation via a Web page required. Same inability to load a page despite a
connection to the WAP. That's what makes this puzzling.

Thanks,

Rich
(Continue reading)

Bengt Richter | 27 Mar 00:03 2012
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Re: Laptop Connects to WAP, But Cannot Access 'Net

On 03/26/2012 12:29 PM Rich Shepard wrote:
> On Mon, 26 Mar 2012, Bengt Richter wrote:
>
>> Could there be an http-only page demanding you agree to terms of use
>> before they open other ports? Have you tried to access with a browser
>> first?
>
> Bengt,
>
>     At the place I tried yesterday, yet. But, when I entered the URL nothing
> happened; firefox just sat there.
>
>     I did not try to reach their web site before establishing a connection to
> their WAP.
>
>> I have experienced apparent inaccessibility on the road just to find out
>> that ports are not opened until you click an agreement to terms-of-use in
>> an http page presented by a proxy I think, and I hadn't seen it because I
>> had tried to get email first, which was a port that was shut off.
>     I've seen this in a couple of the hotels where I stay on business trips,
> and when I cannot ssh to my network I remember that I need to access their
> web site first. But, I was not able to do that yesterday.
>
>     The other location is a coffee shop with unsecured wife access; no
> validation via a Web page required. Same inability to load a page despite a
> connection to the WAP. That's what makes this puzzling.
>
> Thanks,
>
> Rich
(Continue reading)

Rich Shepard | 27 Mar 00:39 2012

Re: Laptop Connects to WAP, But Cannot Access 'Net

On Mon, 26 Mar 2012, Bengt Richter wrote:

> Hm, maybe a DNS problem? Can you put in fixed DNS numbers for your ISP's
> DNS servers to see if there's a problem with automatic DNS, if that's what
> you have going?

Bengt,

   It appears like a DNS issue. At yesterday's site when wicd established a
connection their DNS server filled /etc/resolv.conf with their search domain
name and their two DNS server IP addresses.

> Can you ping a non-local numeric address that you know (maybe determine
> with your dell or other working connection)? Or get there with browser?

   Can't ping anything with the Sony.

> Maybe kernel.org won't mind if you use their number:

   My DNS test domains are www.google.com and my business web site:
www.appl-ecosys.com.

   Yesterday there was no response to either of those or from trying to run
traceroute to either one.

> Hope something jiggles loose ;-)

> Could there be a port 8080 vs 80 problem?
> What does netstat -r tell you?

(Continue reading)

Claudio Fontana | 27 Mar 01:16 2012
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Re: Laptop Connects to WAP, But Cannot Access 'Net

Hi,

On Tue, Mar 27, 2012 at 12:39 AM, Rich Shepard <rshepard <at> appl-ecosys.com> wrote:
> On Mon, 26 Mar 2012, Bengt Richter wrote:
>
>> Hm, maybe a DNS problem? Can you put in fixed DNS numbers for your ISP's
>> DNS servers to see if there's a problem with automatic DNS, if that's what
>> you have going?
>
>
> Bengt,
>
>  It appears like a DNS issue. At yesterday's site when wicd established a
> connection their DNS server filled /etc/resolv.conf with their search domain
> name and their two DNS server IP addresses.
>
>
>> Can you ping a non-local numeric address that you know (maybe determine
>> with your dell or other working connection)? Or get there with browser?
>
>
>  Can't ping anything with the Sony.

then I would not say it is a DNS issue at all.

>> Maybe kernel.org won't mind if you use their number:
>
>
>  My DNS test domains are www.google.com and my business web site:
> www.appl-ecosys.com.
(Continue reading)

Rich Shepard | 27 Mar 01:26 2012

Re: Laptop Connects to WAP, But Cannot Access 'Net

On Tue, 27 Mar 2012, Claudio Fontana wrote:

> then I would not say it is a DNS issue at all.

   Let me summarize the Sony's behavior at 2 different wifi hot spots: wicd
sees nearby networks with the topmost the one at the site where the laptop
is. Clicking on the connect button shows it's connected. However, no web
page loads, and ping, traceroute, and host result in the cursor moving to a
new line and sitting there until ^c is pressed.

   From a console, I ran 'ifconfig -a' and saw that wlan0 was UP and RUNNING.
As root, running 'dhcpcd wlan0' returned an IP address on the LAN. Still
could not ping, run traceroute, or host. Nor would firefox return a Web page
when the URL was entered in the address box.

   The eth0 interface is configured for here and works flawlessly.

   While I've been running only linux since 1997 I'm not a professional
system or network admin; I'm a user. While I can fix more and more problems
that arise when I've encountered them before, this is a new one on me, and
I've been running linux on portables since the late 1990s (and Slackware
since -8.0 in 2003 when I dropped Red Hat).

   If it's not DNS, then what can I run to provide insight into the situation
and pass on the results to you folks?

Rich
Bradley D. Thornton | 27 Mar 02:47 2012
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Re: Laptop Connects to WAP, But Cannot Access 'Net


On 03/26/2012 04:26 PM, Rich Shepard wrote:

>   Let me summarize the Sony's behavior at 2 different wifi hot spots: wicd
> sees nearby networks with the topmost the one at the site where the laptop
> is. Clicking on the connect button shows it's connected. However, no web
> page loads, and ping, traceroute, and host result in the cursor moving to a
> new line and sitting there until ^c is pressed.
> 
>   From a console, I ran 'ifconfig -a' and saw that wlan0 was UP and
> RUNNING.
> As root, running 'dhcpcd wlan0' returned an IP address on the LAN. Still
> could not ping, run traceroute, or host. Nor would firefox return a Web
> page
> when the URL was entered in the address box.
> 
>   The eth0 interface is configured for here and works flawlessly.

Okay I'm not really sure what you're trying to say here. The problem
you're describing is rather elementary, so all I can offer is a few
questions and some textbook troubleshooting procs for the problem you've
described...

1.) You say you did an ifconfig and wlan0 was bound. It is completely
possible to have a layer two connection and not a layer three
connection, meaning, you've connected to the WAP, as you put it, yet
don't have an IP address, mask, or routing info.

It seems that although wlan0-up has occurred, you may not have an IP
address. So let's test, because you say you can't ping *anything*
(Continue reading)

Bradley D. Thornton | 27 Mar 03:04 2012
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Re: Laptop Connects to WAP, But Cannot Access 'Net


oopsie. I left a couple of things out, sort of ;) see below...

On 03/26/2012 05:47 PM, Bradley D. Thornton wrote:
> 
> 
> PING gw (192.168.1.1) 56(84) bytes of data.

In case you were wondering, something akin to the following is in my
/etc/hosts  ;)

<code>
192.168.1.1 gw gateway gloryhole whatev-hostname-you-want
</code>

> <code>
> # echo 8.8.8.8 gnds >> /etc/hosts
> # ping gdns
> </code>

obviously, that's a typo in the echo command. it should have been
'gdns'. All you're doing here is making it possible to ping the DNS
server with any hostname you want assign it with. It would be just as
simple (and more clinical), to do the ping and dig as follows:

<code>
# ping -c1 8.8.8.8
# dig  <at> 8.8.8.8 ibm.com a
</code>

(Continue reading)

Bengt Richter | 27 Mar 02:50 2012
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Re: Laptop Connects to WAP, But Cannot Access 'Net

On 03/26/2012 04:16 PM Claudio Fontana wrote:
> Hi,
>
> On Tue, Mar 27, 2012 at 12:39 AM, Rich Shepard<rshepard <at> appl-ecosys.com>  wrote:
>> On Mon, 26 Mar 2012, Bengt Richter wrote:
>>
>>> Hm, maybe a DNS problem? Can you put in fixed DNS numbers for your ISP's
>>> DNS servers to see if there's a problem with automatic DNS, if that's what
>>> you have going?
>>
>>
>> Bengt,
>>
>>   It appears like a DNS issue. At yesterday's site when wicd established a
>> connection their DNS server filled /etc/resolv.conf with their search domain
>> name and their two DNS server IP addresses.
>>
>>
>>> Can you ping a non-local numeric address that you know (maybe determine
>>> with your dell or other working connection)? Or get there with browser?
>>
>>
>>   Can't ping anything with the Sony.
Including actual dotted number addresses?
what happens if you ping one of the DNS server IP addresses that
you saw in /etc/resolv.conf? That should be a fixed numeric address.

>
>
> then I would not say it is a DNS issue at all.
(Continue reading)

John Crowhurst | 27 Mar 02:25 2012
Picon

Re: Laptop Connects to WAP, But Cannot Access 'Net

On 26/03/2012 23:39, Rich Shepard wrote:
> On Mon, 26 Mar 2012, Bengt Richter wrote:
>
>> Hm, maybe a DNS problem? Can you put in fixed DNS numbers for your ISP's
>> DNS servers to see if there's a problem with automatic DNS, if that's 
>> what
>> you have going?
>
> Bengt,
>
>   It appears like a DNS issue. At yesterday's site when wicd 
> established a
> connection their DNS server filled /etc/resolv.conf with their search 
> domain
> name and their two DNS server IP addresses.

Start with an ifconfig -a to see what IP addresses are assigned to the 
offending machines. It could be that they lack an IP address from DHCP.

If they have a valid IP address, run route -n to give you your routing 
table.

Once you have the gateway IP address, attempt to ping that IP address.

Attempt to ping google by its IP address by looking up the IP address on 
a machine you know works, writing it down on a piece of paper and then 
typing it in.

Run a traceroute -n on google's IP address.

(Continue reading)


Gmane