Very General WIFI Networking Question

[djcyr]

I have a dual-boot windows7- mint13. On some certain wifi networks, I can connect to windows fine, fully functional.
However, under mint, those same networks I can connect, but no internet service is available. Chrome in particular tells me there is a DNS error.

Anything Obvious? Are the networks allowing only windows? Excluding linux users?

representative samples: Queens Borough Public library, Panera WIFI union square

Thanks!

-Dan

[viking777]

Right click the network applet in the system tray select 'edit connections', wireless tab, highlight your wireless connection, press edit, switch to IPV4Settings tab. What does it say under 'Method'? Usually it will say 'Automatic DHCP' If it is set to manual try changing it back to automatic. While you are in there it is a good idea to make sure that 'Available to all users' is checked as well (unless you have some reason to not want certain users to access the internet via wifi).

The first post on this page might be relevant here:

http://forums.penny-arcade.com/discussi ... ns-servers

Basically says that some public wifi firewalls insist on a user using the automatic setting and block outside dns servers.

[djcyr]

Well, I'm back in a different library. I booted linux, verified my network settings as the "Auto" mode, and available to all users as was described. Still no dice. So are you also saying there could be interference if my laptop is running a local DNS server?

Thanks!

[viking777]

The guy in the link I sent you is saying that, certainly. I'm not - I never use public wifi hotspots on my computer so I couldn't say one way or another for sure. However the results of your experiments seem to suggest this is not the case, at least no in the library you are using. In which case I am not sure what the answer is, sorry.

[Detonate]

Please run

Code: Select all

cat /etc/resolv.conf

and post the results.

[djcyr]

Now I am in another public library. Same story, I can connect with windows to wireless ssid HPLRC, but in Mint 13 Google Chrome says my DNS is unresponsive.

Why or how can a wireless work in windows and not in Linux?


I do not have a resolf.conf file. There is a directory /etc/resolvconf that contains:

interface-order file

resolv.conf.d update.d update-libc.d directories


interface-order contents:

# interface-order(5)
lo.inet*
lo.dnsmasq
lo.pdnsd
lo.!(pdns|pdns-recursor)
lo
tun*
tap*
hso*
em+([0-9])?(_+([0-9]))*
p+([0-9])p+([0-9])?(_+([0-9]))*
eth*
ath*
wlan*
ppp*
*
/etc/resolvconf/resolv.conf.d $ ls -al
total 12
drwxr-xr-x 2 root root 4096 Sep 18 2012 .
drwxr-xr-x 5 root root 4096 Sep 18 2012 ..
-rw-r--r-- 1 root root 0 Mar 29 2012 base
-rw-r--r-- 1 root root 151 Mar 29 2012 head

etc/resolvconf/resolv.conf.d $ cat head
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN

[djcyr]

Can anyone help me as to why, and what all this network stuff means? Why is it stopping me from using public internet service in a public library?

[pfeiffep]

Can anyone help me as to why, and what all this network stuff means? Why is it stopping me from using public internet service in a public library?

The New Your public Library system is more than likely NOT discriminating against Linux. Since the exact same hardware configuration works for you using Win the most obvious stumbling block is your Linux configuration.
I suggest booting to Win and insuring internet connectivity - then while in Win discover the DNS that is being used, or the method to detect DNS
Reboot to Linux and insert the Win DNS server or choose a similar method to detect.

[djcyr]

At the public library, I repeatedly boot into Windows, and can connect fine to the Internet.
Many, many times here at the library, I have booted into mint, and each time have not been successful connecting to the Library's wifi.

Wifi works fine at home.

Made a USB stick with Fedora 18, and can connect to the library. How did my mint become broken here?

Chrome says DNS unresponsive. Can you lead me in any other direction?

[pfeiffep]

OK now you've proven that my assumption that Linux Mint was causing the problem

Did you attempt to follow or understand

I suggest booting to Win and insuring internet connectivity - then while in Win discover the DNS that is being used, or the method to detect DNS
Reboot to Linux and insert the Win DNS server or choose a similar method to detect.

You now have another working option from which to choose settings - Fedora. You shouldn't have to go to the Library to discover the DNS entries for the 3 OSes that you've tried.

Obviously your hardware is just fine, and Win & Fedora must have different network settings than Mint. I propose that you proceed with the basic assumption that nothing's really broken but rather there's a setting incompatible in Mint that won't work at the Libraries!

Asking how isn't necessarily going to remedy your situation - trying different options (as you did with Fedora) can lead you to a solution

Post back with your results........

[trapperjohn]

Force feed the DNS server. In your IP4 settings use "automatic DHCP addresses only." Then specify the DNS servers in the box. Use the Google DNS as an experiment: 8.8.8.8,8.8.4.4

If that works, then take a look at other dns servers like opendns. You separate the DNS IPs with a comma.

[djcyr]

I was asking how as a remedy, because I need help to connect, and wanted to consult with experts who may focus on networking for a living.

Why does mint need to be spoonfed such DNS help? Is it mis-configured for certain routers? Maybe Panera and Queens library share a certain network config that may be wrong, or maybe mint should be able to handle all kinds of public wifi routers.

[trapperjohn]

Hi,

If using the staticly assigned DNS works, then underlying problem is with the assignment of domain name servers by the router (and ultimately the ISP). A router can be ( and usually is) configured to obtain both a WAN IP address and a DNS assignment by the DHCP. Using the DNS provided by the ISP's DHCP server is not necessarily the best choise.

I prefer not to use a DHCP provided default DNS. The Google DNS (8.8.8.8 and 8.8.4.4) and the OpenDns ( 208.67.222.222 and 208.67.220.220) are quite fast and bug free compared to most ISP DNS choices. They may even be more private, depending on the integrity of the DHCP server. Even with Windows machines that I manage I opt for statically assigned domain name servers.

If you can use any of the static DNS servers for OpenDNS or Google and cannot use the default DHCP DNS, then it tells us that the default DNS is qualifying your access in someway... and I perfer not to grant any custom control to networks when I have a choise.

If using a static DNS does not solve the problem, then there is some other wrinkle we need to iron-out. But, if it does work, use the static DNS approach. It will not limit your online capabilities and, in many cases, it will provide improved performance, capability, and posibility privacy.

[bjornmu]

It may be something else. I experienced with a wifi network in Larnaka that my Linux (not mint) laptop could get no connection though the wifi seemed OK. But it was not about DNS, instead the server had not provided a default routing address. Try the command "route" and see if you get an address under Gateway for the destination 'default'. If not then you have the same problem. What I eventually had to do was to add it manually (as root, or with sudo), guessing that the IP address of the default router was the same as the DHCP server. I think the command will be:

Code: Select all

sudo route add default gw <IP addr>

Addendum: another symptom of that problem is that nothing is reachable even with an IP address. If you can successfully ping 8.8.8.8 then you do not have this problem.