Category Archives: Servers

Getting Wireless LAN Working in Linux using ifcfg and wpa_supplicant over WPA2_Personal with AES

This took me almost a full day to figure out so I figure I write down what I did for reference and for others benefit, seeing as I optimized my titles, tags and content. Makes it easier to find this site when using the searches I did to get to the information. I had to piece this together from multiple posts and instructions as each one didn’t work exactly right.

So, I recently got AT&T uVerse, and after configuring it accidentally with a WEP Open Shared Key, realized that not only is it not secure, but some devices have major problems connecting to it. Sometimes I would have a visitor with a laptop come over and the wi-fi just wouldn’t work.

I know Windows 7 has some issues connecting to an older less secure network, in fact, I have found myself having to manually configure networks sometimes in order to get it working if a network is using WEP, the automatic detection just fails. On my network however, even windows XP was failing, so it was time to change. I decided to go with WPA2_Personal using AES Encryption.

Everything was fine, all myd evices connected happily, even the linux box…taht is until I decided ot try to configure it using ifcfg and not Fedora’s built in whatever it is…

I knew how to bind eth0 style devices to my network, but I had never had to do it wirelessly, needless to say the need arose only because my wife decided that it was not acceptable to have a long wire running from the bedroom to the living room to use the extra PC as a server…hence the wireless solution! (At least now I don’t trip over the cord at night!)

I wont bother to bore with the details of the errors I was getting, so, after much frustration, here is how I figured out how to do it:

Manually Adding IP Address Range to Linux – Fedora and Redhat – Thanks @Softlayer

Thanks to Softlayer for this handy tutorial, worked like a charm adding my new IP Range.

1. Determine what existing range files exist:

# cd /etc/sysconfig/network-scripts/

# ls ifcfg-eth1-range*

You will see at least one file, possibly several. Find the highest number following the “range” and add one to it. This will be the new range number.

For example, if you see ifcfg-eth1-range0 and ifcfg-eth1-range1, your new range number will be “2″ ie: ifcfg-eth1-range2 .

2. Determine the next available interface number (clone number).

# ifconfig | grep eth1

You will see a list of interfaces that looks like this
eth1 Link encap:Ethernet HWaddr 00:08:74:A3:29:70
eth1:0 Link encap:Ethernet HWaddr 00:08:74:A3:29:70
eth1:1 Link encap:Ethernet HWaddr 00:08:74:A3:29:70
.
.
.
eth1:8 Link encap:Ethernet HWaddr 00:08:74:A3:29:70

Find the highest number after the “eth1:”. Add one to it and this your new clone number. In this case it would be 9.

3. create a range file for the new range number. (for this example, we will use range3)

# vi ifcfg-eth1-range2

4. Write the following lines to the range file. (replace the dummy ip information with your desired ip range and the CLONENUM_START value with the one calculated above)

IPADDR_START=’123.0.0.1′
IPADDR_END=’123.0.0.10′
CLONENUM_START=’9′

5. Write and quit the range file, and restart your network.

# /etc/init.d/network restart

6. Your new ips should now be visible by running:

# ifconfig