Wifi Connectivity

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Revision as of 04:59, 12 February 2014 by Quozl (talk | contribs) (no future plans for mesh)
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This page is part of the XO Support FAQ.     Support Index | Print This Page
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Overview

XO laptops were designed for children in developing nations, where it is faster and less expensive to introduce wireless connections, rather than traditional cabled infrastructure. The XO Laptop is designed to network with other XO Laptops using a mesh network or an adhoc network, but the XO is also capable of using infrastructure networks provided by an access point.

An XO laptop cannot be on both the Internet and on the mesh network at the same time.

Getting Started

  • you must have a wireless access point nearby,
  • verify the network name (SSID) and its password, if it has one, and;
  • follow the 8.2.0 instructions.

Hidden Networks

A wireless network may be hidden. This does not make the network more secure, but it is occasionally done.

Unlike normal networks, a hidden network will not be visible in the Neighborhood View.

To connect to a hidden network, follow the steps in the section below that corresponds to the operating system version on the XO.

10.1.3 and 11.2.0

Using a hidden network in GNOME is straightforward; left-click on the wireless icon and select "Connect to Hidden Wireless Network...".

Using a hidden network in Sugar is far more complex. You must switch to GNOME, reconfigure Network Manager, restart Network Manager, connect to the hidden network, mark the network available to all users, then switch back to Sugar.

The procedure in detail is:

  • Use "My Settings" to switch to GNOME,
  • Edit the file /etc/NetworkManager/nm-system-settings.conf
sudo gedit /etc/NetworkManager/nm-system-settings.conf
  • Change plugins=ifcfg-rh to plugins=keyfile, then save,
  • Restart Network Manager,
sudo /etc/init.d/NetworkManager restart
  • Locate the wireless icon, it should be to the left of the date and time on the top right of the screen,
  • Left-click on the wireless icon and select "Connect to Hidden Wireless Network...", and a window with that title will appear,
  • Enter the hidden network name and click on "Connect", and the wireless LED should flicker and then glow,
  • Verify you can reach the internet using Firefox or some other GNOME application,
  • Right-click on the wireless icon and select "Edit connections...'", and a "Network Connections" window will appear,
  • Click on the "Wireless" tab,
  • Click on the hidden network entry you created, then on "Edit", and an "Editing hidden" window will appear,
  • Turn on "Connect automatically", if it isn't already, (near the top of the window),
  • Turn on "Available to all users", (near the bottom of the window), and;
  • Click "Apply",
  • Switch back to Sugar.

The connection to the hidden network will be made automatically whenever the laptop is booted, regardless of whether Sugar or GNOME is running. The connection will remain active over restart of Sugar or GNOME.

8.2.1

Every time the laptop is started up, a hidden network must be manually added through the Terminal Activity: 

su -l
/etc/init.d/NetworkManager stop
/sbin/iwconfig eth0 mode managed essid myhiddennetwork
/sbin/dhclient eth0
exit

After this, Neighborhood View should show any other XOs on the same access point, and Browse should be able to reach the internet. A symbol for the access point will not be displayed.

Special Considerations

Wireless Access Point Setup

The OLPC Support Team has been gathering notes and configuration tips for various Wireless Access Point (WAP) connectivity. We are actively working to resolve minor compatibility issues with various Wireless Access points.

Some key setup considerations for your Wireless Access Point are:

  • A single channel should be selected, not "Automatic"
  • Preferred Channels are 1, 6, and 11
  • The wireless network mode should be "Mixed" or "Wireless-G", not "Disabled" or "Other"
  • If Wireless MAC Filtering is enabled, the MAC address for the XO must be entered
  • The latest Firmware should be loaded on your access point
  • Make sure that there are only alphanumeric characters and no spaces in your network name, or SSID.

Channel

With 802.11b or 802.11g, use channel 1, 6 or 11 in the US or Canada. Use of any other channels will degrade your own wireless signal and that of others.

Similarly, the mesh networking and adhoc network between XO laptops is restricted to work only on channels 1, 6 or 11.

Security

What is the difference between a key and a passphrase?

When you try to connect to a secured (encrypted) network your XO has to send an encryption key to the access point. This key is derived from the passphrase you chose when you configured your access point (and also from the ESSID, if you are using WPA).

So, the passphase is the long password that is relatively easy to remember while the key looks like a random sequence of characters. The length of the key varies depending on the type of security and it is usually represented in its Hex form, meaning that it will be formed by a sequence of digits and letters from A to F.

With WEP, the conversion from passphrase to key is not standardized and therefore is different on various companies' access points. Also, the WEP example below is only for 104/128 bit WEP. It will not work on 40/56 bit WEP. For these and other reasons, use WPA if you can.

Here is one example, for WEP:

Here is another example, for WPA-PSK:

  • Key length: 256 bits
  • PassPhrase: MyPassPhrase
  • ESSID: MyEssid
  • Resulting key (64 characters long): c3044f3fbd077e236d12f0b1f9d7761e0e6de266783d843d76edf1da3131bff6
  • Converted using: http://www.xs4all.nl/~rjoris/wpapsk.html

WEP Security

WEP Security is built in to the XO.

If you have a WEP pre-shared key, it can be set within the Terminal Activity: 

su -l
/sbin/iwconfig eth0 key 381E966F1EAE4140F83D30C201
exit
  • /sbin/iwconfig sets the WEP key in the XO to match your WAP (of course, substitute your WEP pre-shared key for the 381E966F1EAE4140F83D30C201 in the above example).

WPA Security

WPA security requires extra steps.

The XO is known to be unable to connect to certain Access Points when those networks are configured with WPA security. It is unfortunately not possible to classify such access points without detailed technical diagnosis on a case-by-case basis. See <trac>7825</trac> for the technical details. If you are unable to connect to your WPA access point, you may consider switching to WPA2 (RSN) which is not affected by this flaw.

MAC Filtering

Wireless MAC Filtering is a security measure that restricts access to the WAP by MAC Address. Every computer or other peripheral has a unique HEX address assigned at the time of manufacture.

The MAC address for the XO is displayed using the Linux command ifconfig.

Note: You will find ifconfig in the /sbin directory, which is not in the default path. Type /sbin/ifconfig

Specific WAP Notes

A matrix of Wireless Access Point Compatibility is being updated by the support community.

Actiontec

Various issues have been reported with Actiontec WAPs. Most seem to resolve after a firmware upgrade of the WAP, and following the setup instructions.

Apple Airport

There are two kinds of Apple Access points: WEP and WPA.

If you have WEP:

  1. Go to: http://www.corecoding.com/utilities/wep2hex.php and convert your password into a hex phrase.
  2. Click on the Access Point in the neighborhood view Mesh key f1 small.png.
  3. Choose Hex input for the key; and choose "shared" key instead of "open".
  4. Enter your hex phrase.
  5. You should be able to associate to and authenticate a connection to an Apple Access point.

If you have WPA, you should note that WPA is not working from the User Interface in build 650. You should upgrade to build 653.

  1. To Find your WPA password, follow Apple's Getting an equivalent network password instructions.
  2. Click on the Access Point in the neighborhood view Mesh key f1 small.png.
  3. Enter Hex input, TKA

Verizon FIOS

The XO cannot connect to ActionTec M1424WR unless the router must be set up to use one channel exclusively (1-11) rather than rotate the channel selection.

From a computer other than your XO:

  1. Go to your Browser, and type in 192.168.1.1
  2. A screen will open, and you will need to insert your username and password. The default login is admin / password .
  3. Another new screen will open. Along the top you will spot "Wireless Settings." Select that category.
  4. Along the left side you will see a column. Choose "Basic Security Settings."
  5. Look for Section 3. Channel: ______________ If it says "Automatic." it is rotating through eleven channels. Choose just one channel, preferably 1, 6, or 11.
  6. Click the "Apply" button.


Here's another option THAT WORKS to connect to Verizon WEP by:CareBearOne. edited by:Micah. 1 - from the "Terminal Activity" window...type su -l (username here) to get into superuser mode. 2 - type /sbin/iwconfig eth0 key <your WEP key not the passphrase> 3 - type /sbin/iwconfig <--to see the current wireless configuration. 4 - type /sbin/ifconfig <--to see the current ethernet configuration. 5 - type /sbin/dhclient eth0 <--to run the dchp script so your laptop will be assigned an IP address. 6 - type /sbin/ifconfig <--to see the ip address your laptop has been assigned.

Now I need to figure out how to put this in a script!!! Anyone know?? ________________________________________________________________________________________________________________________________

No, but I do know that I have that excact same problem. The XO will display the router, but when you click on it it will either just flash, or it will display the box that tells you to enter the passcode for the router. And when you do (even if you have done it correctly), it will atttempt to connect, then the box will pop back up.

-Micah

Belkin Pre-N

Some access points that have reported intermittent problems with XOs:

  • BelkinPreN - XO Connects but all other systems disconnect

If you have one of these access points, please contact technical support if none of the basic setup fixes solves your connection problem.

Linksys WRT54GX2

Some access points that have reported intermittent problems with XOs:

  • Linksys WRT54GX2 [and WRT54GX4] - XO Connects but cannot access internet

If you have one of these access points, please contact technical support if none of the basic setup fixes solves your connection problem.

Troubleshooting

Remove networks.cfg file

(8.2.1 or earlier only)

If you have attempted to connect to a password-secured WPA or WEP access point and were unsuccessful, or if you have changed your Access Point settings, then you may need to remove the networks.cfg file, which has saved your password and continues to try the old password (see below).

From the Terminal activity or a console, type: 

rm /home/olpc/.sugar/default/nm/networks.cfg

or if file don't exist: 

rm /home/olpc/.sugar/default/nm/connections.cfg

and press [Enter].

XO Setup

networks.cfg

(8.2.1 or earlier only)

The networks.cfg file contains information about the current network configuration from session to session.

If you want to remove any "memory" of connecting to a particular access point or if you change the configuration of your Access Point (such as adding or removing security features), then you will need to remove this file in order to get your XO to connect to the Access Point.

  • to see which networks are currently in your known networks file type:
 more /home/olpc/.sugar/default/nm/networks.cfg            (press "Enter")
  • to delete the network manager config file by typing:
rm /home/olpc/.sugar/default/nm/networks.cfg    (press "Enter")

Restart your XO laptop, or restart Sugar by pressing the Ctrl+Alt+Erase keys at the same time; your laptop will NOT automatically try to connect to the "known" access point.

Proxy Settings

The initial software build on the Give1Get1 shipped in December 2007 (Build 650) does not support a user interface to change the web browser by proxy settings. You can change your preferences by creating a user.js file in /home/olpc/.sugar/default/gecko - the browsers profile folder.

The file should look like this: 

pref("network.proxy.http",  "<set to your proxy server>");
pref("network.proxy.http_port",  <set to 8080 or the appropriate port>);
pref("network.proxy.type",1);

or you can use the autoconfig: 

pref("network.proxy.autoconfig_url", "<your proxy>");

On more recent builds, to change your browser's proxy settings: enter "about:config" into the browser's url field. This will load the configuration page for the browser. There are three settings you must change to work with a proxy: 

network.proxy.http       <set to your proxy server>
network.proxy.http_port  <set to 8080 or the appropriate port>
network.proxy.type       <change to 1>

To change a setting, double-click on a line and type the new setting into the space provided, however there have been many complaints that this method doesnt work http://en.forum.laptop.org/viewtopic.php?f=2&t=150578#p543444.


How to Connect to the Virtual Mesh

There used to be a public XO server at xochat.org. This server got overloaded with connections and shut down, there currently aren't any public XO servers. Public XO servers are available at Community Jabber Servers.

  1. Open the Terminal activity.
  2. Type the following to see your current setting:
    • sugar-control-panel -g jabber
  3. Type the following to set the XO to connect to the server:
    • sugar-control-panel -s jabber server.name
  4. Reboot Sugar with Ctrl+Alt+Erase.

Troubleshooting Guide

The Wifi Troubleshooting Guide provides a step by step checklist to review prior to contacting Technical Support.

See also

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