Tag Archives: WiFi

How to PPTPD (PopTop)

Below is a way to connect your clients like smartphone, laptop, etc to the Internets while you are out and about connecting to random WiFi networks etc like Mac Donalds, and to help protect yourself while on them unknown networks with unknown users

Install mppe kernel support

# modprobe ppp-compress-18

Install PPTPD

# apt-get install pptpd

Configure IP Address Range
Edit the file /etc/pptpd.conf for the IP address range

localip 172.16.100.1
remoteip 172.16.100.200-250

restart pptpd to activate changes

# invoke-rc.d pptpd restart

Adding users accounts
Edit the file /etc/ppp/chap-secrets

test_user * lamepassword *

The above will give you a working PPTPD where your able to connect to securely but you’ll most probably can’t connect to the outside network.

To allow you PPTP clients access to the big bad internet

Enable IPv4 forwarding

echo 1 > /proc/sys/net/ipv4/ip_forward

Finally configure your iptables

iptables -A INPUT -i ppp+ -j ACCEPT
iptables -A OUTPUT -o ppp+ -j ACCEPT
iptables -A POSTROUTING -t nat -o eth0 -j MASQUERADE
iptables -A POSTROUTING -t nat -o ppp+ -j MASQUERADE

If you want all traffic to go through the PPTP connection
Edit the file /etc/ppp/pptpd-options and change

# Debian: do not replace the default route
nodefaultroute

to

# Debian: do not replace the default route
#nodefaultroute

and don’t forget to restart pptpd ;-)

Reference
Debian pptpd HOWTO
IP Chicken

Building ~6dBi Collinear WiFi Antenna

This is little bit of info about the ~6dBi WiFi Antenna I have built. All up it took me about 2 hours to make and build the Antenna. All that is left to do is test the Antenna to see how good it works and that it is on frequency.

The materials required:

  • approx 300mm 1.6mm copper wire
  • panel-mount female N-connector
  • 250mm length of 20mm light-duty electrical conduit
  • 2 end-caps to suit 20mm conduit

Design Details
This collinear simply consists of a length of copper wire with some loops located at specific locations. The dimensions of the sections of the antenna are important, and are shown in the diagram below.

dimensions of the collinear
Image sourced from martybugs.net

The length of the bottom section is 1/2 wavelength, the centre section is 3/4 wavelength, and whip section on the top is slightly less than 3/4 wavelength, apparently to reduce the capacitance effect.

The 802.11b standard uses 2.412MHz to 2.484MHz frequency range, so at the centre of that frequency range, 1/2 wavelength is 61mm, and 3/4 wavelength is 91.5mm.

These dimensions appear to be consistent with similar commercial antennas.

Pictures:

Reference:
Home-brew Compact 6dBi Collinear Antenna

Acer Aspire Timeline 4810T laptop and Wireless under Debian 5.0.2 (Lenny)

$ lspci
….
02:00.0 Network controller: Intel Corporation Wireless WiFi Link 5100
….

Add the Debian Backports repository to /etc/apt/sources.list

deb http://www.backports.org/debian lenny-backports main contrib non-free

Update the list of available packages and install the debian-backports-keyring package.

# apt-get update
# apt-get -t lenny-backports install debian-backports-keyring

As your system does not yet have the GnuPG archive key of the backports.org repository installed, you will be asked to confirm installation of a package from an untrusted repository. Enter Yes when prompted.

Install a 2.6.30 kernel image appropriate for your system, along with the firmware-iwlwifi and wireless-tools packages.

# apt-get update

# apt-get -t lenny-backports install linux-image-2.6.30-bpo.1-$(uname -r | sed 's,.*-,,g') firmware-iwlwifi wireless-tools

Restart your system and boot with the newly installed kernel, and the necessary kernel module should be automatically loaded.

As the new kernel was booting I noticed it made mention to that the microcode was out of date. To fix this problem simply download the new microcode from Intel Wireless WiFi Link Drivers for Linux.

wget -c http://intellinuxwireless.org/iwlwifi/downloads/iwlwifi-5000-ucode-8.24.2.12.tgz

Uncompress the microcode

tar xvf iwlwifi-5000-ucode-8.24.2.12.tgz

Now all we need to do is to change into the directory of where the microcode is and then copy it to /lib/firmware

# cd iwlwifi-5000-ucode-8.24.2.12/
# cp iwlwifi-5000-2.ucode /lib/firmware/

Restart your system and the newly added microcode will be loaded and used.

Connecting to secure wireless network without authenticating against keyring manager

From : original link

By default, if a wireless network is secured by WPA or such, you have to save the info in your keyring manager, which is protected by a password.

Both session and keyring passwords must match for this to work, if they don’t match, you will be prompted to unlock the keyring.

1. Install libpam-keyring package :

$ sudo apt-get install libpam-keyring

2. Then tweak the GDM PAM (plugable authentication module) security

$ sudo gedit /etc/pam.d/gdm

Add the following line at the very end of that file, then save :

@include common-pamkeyring

3. Reboot and authenticate into your session, you should now be connected.

4. Optional : change your keyring password

$ /usr/lib/libpam-keyring/pam-keyring-tool -c