CentOS - Feb 2010 - Internet access not working on CentOS but on Windows when travelling

Hello,

I'm currently travelling (in south-eastern Europe) with a netbook
(Samsung NC 10) running CentOS 5.4 i386.
I frequently try to access internet from bars or hotels (mostly via wireless).

Although it works pretty often, it happens quite regularly that in
some hotels I cannot access internet from CentOS while it is possible
from Windows.
This is the case in the hotel where I am currently and I'd like to dig
this further.

To be more precise:
- in such cases, connecting to the wireless network itself works
(using NetworkManager)
- this is when I try to open a web page in Firefox that after a while
I get a "page not found exception"
- there is no problem on a Windows XP which is also installed on the computer
- Fedora 12 has the same issue as CentOS
- I suspect that in such cases the network is configured in a
windows-specific / non-standard manner (but I had the pb often enough
to justify addressing it): I installed Samba and started the winbind
service, but it did not help (I know pretty much nothing about Windows
networking but doing this already did some magic for me in other
contexts...)
- there are many places where I could connect with CentOS and wireless
without any problem, and it also work in my wireless network back
home, so my CentOS config is OK
- interestingly, my google phone (G1 running Android 1.6) could access
internet via the wireless network of the hotel where I am currently
(while CentOS and Fedora can't)

Did anyone already face such an issue?
Any idea how I could analyze further?
Or what I could try?

This is not a big deal since I can always reboot to check internet,
but all the software I use for my work are on CentOS, so it would be
much more practical if I could reliably access internet from it as
well.

Thanks in advance and cheers from the Black Sea under the snow...

Mathieu

From: Mathieu Baudier <mbaudier at argeo.org>
> I'm currently travelling (in south-eastern Europe) with a netbook
> (Samsung NC 10) running CentOS 5.4 i386.
> I frequently try to access internet from bars or hotels (mostly via
wireless).
> Although it works pretty often, it happens quite regularly that in
> some hotels I cannot access internet from CentOS while it is possible
> from Windows.
> This is the case in the hotel where I am currently and I'd like to dig
> this further.
While you cannot access websites, did you test with their IPs instead?
Also try a traceroute.

JD

Mathieu Baudier wrote:
> Hello,
> 
> I'm currently travelling (in south-eastern Europe) with a netbook
> (Samsung NC 10) running CentOS 5.4 i386.
> I frequently try to access internet from bars or hotels (mostly via
wireless).
> 
> Although it works pretty often, it happens quite regularly that in
> some hotels I cannot access internet from CentOS while it is possible
> from Windows.
> This is the case in the hotel where I am currently and I'd like to dig
> this further.
> 
> To be more precise:
> - in such cases, connecting to the wireless network itself works
> (using NetworkManager)
> - this is when I try to open a web page in Firefox that after a while
> I get a "page not found exception"
> - there is no problem on a Windows XP which is also installed on the
computer
> - Fedora 12 has the same issue as CentOS
> - I suspect that in such cases the network is configured in a
> windows-specific / non-standard manner (but I had the pb often enough
> to justify addressing it): I installed Samba and started the winbind
> service, but it did not help (I know pretty much nothing about Windows
> networking but doing this already did some magic for me in other
> contexts...)
> - there are many places where I could connect with CentOS and wireless
> without any problem, and it also work in my wireless network back
> home, so my CentOS config is OK
> - interestingly, my google phone (G1 running Android 1.6) could access
> internet via the wireless network of the hotel where I am currently
> (while CentOS and Fedora can't)
> 
> Did anyone already face such an issue?
> Any idea how I could analyze further?
> Or what I could try?
> 
> This is not a big deal since I can always reboot to check internet,
> but all the software I use for my work are on CentOS, so it would be
> much more practical if I could reliably access internet from it as
> well.
Check your dns settings after the network comes up.  It sounds like 
networkmanager is not rewriting /etc/resolv.conf with the servers picked up from
the local dhcp service.  If you are running your own DNS server, it may be that 
some places block direct access to port 53.

-- 
   Les Mikesell
    lesmikesell at gmail.com