How to scan for wireless networks

[smittypaddler]

I'm trying to get away from Microsoft, which is why I've set up FC6
in it's own dual-booted partition on my laptop. But I don't know much
about wireless connections in Linux. At home I use static IP addresses
and have one Linux machine doing IP masquerading/forwarding, and all
my other computers use that one machine as their default route. When
I travel I boot Windows/XP on my laptop, click on Start->Control
Panel->Network Connections->Wireless, tell it to scan for available
connections, and it gives me a list, showing the signal strength of
each one it finds, and I tell it which one to connect to. Then I
boot Linux under VMware, and do all my work there, using Evolution
for my mail, and Mozilla/Firefox for my browser. Although I have
Norton Antivirus, and always run through a firewall on my Windoze
host, I never run any applications that access the Internet through
Microsoft Windoze. First, I refuse to buy a license for things like
MS/Outlook, and second, I'm convinced my computer is much safer doing
it this way. Can anyone direct me to a tutorial or how-to on making
wireless connections while traveling using Linux?

[Jman]

Basically start the NetworkManager service. An icon should appear in notification area, click on it for a list.

[gthill]

man iwlist
man iwconfig

[glynixx]

Hi. Here is a few command I had to use recently to get my wireles up and running and maybe they can help you too.

First you need to see if your wireless card is up and running so please do the following from a command line:

ifconfig

this is the same as ipconfig as it will tell you if you have a card (probably wlan0 or 1 typically, sometimes eth1 (as eth0 should be your built-in nic)).

See if you have an ip. To make sure your card is up you can do ifconfig wlan0 up
(you can substitute wlan"x" for whatever you are shown)

now you can use "iwlist wlan0 scanning" to scan the networks around you.

to configure your wireless card you need to do 3 things (all of which you may have already done of FC may have done for you). This is mainly to setup your card, do dhcp, etc.

You will need ifconfig to turn the card up and assign a static ip if you are not doing a dhcp. You use dhclient to obtain a dhcp address. You use iwconfig to setup your card.

I recommend that you follow gthill suggestion to do a little reading on those manual (help) pages.
The stuff I put in ( ) are just descriptions so dont type the commands

for instance:
iwconfig (to see any wireless cards you have listed, lets assume you do see wlan0)
iwconfig wlan0 essid <ESSID> (where essid is the name of your wireless network)
iwconfig wlan0 ap <AP> (where <AP> is the mac address of your access point, may not be needed if you are broadcasting).
iwconfig wlan0 key <open or another setting, see manual page> <wep key> (if using wep)
iwconfig wlan0 <managed> (may not be needed)


turn up the interface:
ifconfig wlan0 up

get an address:
ifconfig wlan0

to manually assign an ip:
ifconfig wlan0 <ip> netmask <subnet mask>

and if you need to setup a gateway you can do it with the route command.

Here is a great site for commands if you in a windows pc and need to look them up and do not have access to a linux pc.
http://www.linuxcommand.org/man_pages/iwconfig8.html

Hope all this helps. Also I've only worked this for a little over a week so please to defer to those who have been here longer.

G.

[smittypaddler]

Hello all. I'm sending this via a wireless connection in my hotel
in Hawaii. It was indeed fairly simple to make the connection using
NetworkManager. Here's a few notes that might help the next fellow
going from a static IP address to a dhcb-enabled one. First, I did
this to get NetworkManager started at boot:

/sbin/chkconfig --level 345 NetworkManager on
/sbin/chkconfig --level 345 NetworkManagerDispatcher on
/sbin/chkconfig --level 345 dhcdbd on
/sbin/chkconfig --level 345 named on

If there is no network connection, the icon on the toolbar for the
NetworkManager is a cable-and-plug with a red circle and diagonal bar over it.
If you click on it, it will give you a list of available access points,
each with a green bar showing signal strength. You can click on one
to get it activated. If the connection succeeds, you'll get a message
"Connection Established" and the icon changes to a set of conjoined
vertical rectangles increasing in height from left to right, some number
of which, starting from the left, will be colored green to show signal
strength.

I was a bit puzzled how eth1 got started at boot, since my
/etc/sysconfig/network-scripts/ifcfg-eth1 file contains ONBOOT=no,
until I found this message in /var/log/messages: Oct 13 11:21:32
waikiki NetworkManager: <information> Activation (eth1) successful,
device activated. Note that this did not work at boot until I removed
those lines defining eth1 as statically configured for my LAN at home:

NETMASK=255.255.255.0
IPADDR=192.168.1.13
GATEWAY=192.168.1.10

[glynixx]

Great news!!

[RobG]

Hey... I just found this thread today. It appears my wireless card is working, but what's lacking is support for the WPA-Personal encryption method. Is this something I can add somehow? I'm on FC7, computer is a Dell 1520 laptop with the 3945 wireless.

I was checking the manpages for iwconfig and it doesn't let you specify the encryption type, and the graphical version in Control Center only seems to support WEP. Interestingly enough, this Dell won't talk to my Linksys router if I use WEP; that's why I switched to WPA-Personal.

Rob