====== Εγκατάσταση - Ρύθμιση ασύρματης κάρτας δικτύου ======

===== Περιγραφή δικτύου =====

Θέλουμε να ρυθμίσουμε το παρακάτω δίκτυο
  - Έναν ενσύρματο router (AdslRouter) με ip π.χ. 10.64.53.1 που είναι πύλη για το internet
  - Έναν ασύρματο router (WRouter) με ip π.χ. 192.168.2.1 που είναι και αυτός πύλη για το internet
  - Έναν server υπολογιστή με ip 10.64.53.200 στην ενσύρματη θύρα και 192.168.2.200 στην ασύρματη
  - Client υπολογιστές που να μπορούν να δρομολογούνται προς το internet μέσω του server υπολογιστή. Ο server θα έχει ρυθμίσεις που θα μπορούν να εναλλαχθούν ώστε να δρομολογήσει είτε μέσω του AdslRouter είτε μέσω του WRouter

===== Εγκατάσταση ασύρματης κάρτας =====

Αρχικά θα εγκαταστήσουμε το απαραίτητο λογισμικό (βλ. [[el:linux:debian:desktop:hardware:wireless#gss_lgs_g_s]] )



For wpa see instructions below and 
  man wpa_supplicant 
to select driver, generally wext will be the correct  


Check connectivity with
  ping 192.168.2.1 #Wrouter
  ping 192.168.1.254 # Adsl Router
  nslookup www.google.com # dns check
  ping www.google.com

To finish up (if not already done so) set the EthRouter as a Router
  /etc/init.d.myrouter start
Now set the eth0 interface of the EthRouter to address 10.64.53.200 with
  ifconfig eth0 10.64.53.200
You could use a dhcp server on EthRouter and assign an address to the client pc through dhcp but another 2 dhcp servers exist and routers can route to them and things may get mixed up. Ofcourse if this client pc is running linux adjusting the /etc/dhclient.conf to reject offers from 192.168.1.254 (AdslRouter) and 192.168.2.1 (Wrouter) will do
  reject 192.168.1.254;
  reject 192.168.2.1;
So for simplicity we will set a static ip like 10.64.53.201 to the client pc . 
  ifconfig eth0 10.64.53.201
  route add default gw 10.64.53.200 # EthRouter

Change also manually the /etc/resolv.conf to set the dns servers
  nameserver 192.168.2.1 #Wrouter
  nameserver 192.168.1.254 #AdslRouter

Now test connectivity in the client pc with
  ping 10.64.53.201	# EthRouter
  ping 192.168.2.1	# Wrouter
  ping 192.168.1.254 # AdslRouter
  nslookup www.google.com # dns resolution
  ping www.google.com # internet connectivity
We did it!
Ofcourse we need to change /etc/network/interfaces files to use this configuration automatically on reboot.
In the EthRouter add this to /etc/network/interfaces
  allow-hotpug wlan0 eth0 # to regain connection if WRouter is restarted
  iface eth0 inet static
  address 10.64.53.200
  netmask 255.255.255.0 # 
  iface wlan0 inet dhcp
  wireless_essid wrouter #your WRouter ssid
  # (optional) uncomment line below to ensure ndiswrapper is loaded
  #pre-up grep -q ndiswrapper /proc/modules || modprobe ndiswrapper

  /etc/init.d/networking restart
  /etc/init.d/myrouter start

Now redo the connectivity checks from the client pc. 
Finally shutdown EthRouter, reboot and check again from the client pc. If all ok you are done!

You would like to secure your wirelless network, and therefore enable wpa encyption disabling ssid broadcast.

FOR WPA checkout http://www.vollink.com/gary/deb_wifi.html
See also latest changes for smoother integration in debian Etch 4.0
http://wiki.debian.org/WPA
http://svn.debian.org/wsvn/pkg-wpa/trunk/wpasupplicant/debian/README.modes?op=file&rev=0&sc=0

wpasupplicant package is depreciated now and simpler intergation to /etc/network/interfaces can be used.
Before we use it update to the latest netbase package
  apt-get install netbase
And ofcourse install the wpasupplicant package
  apt-get install wpasupplicant
For our example if we have wpa tkip/psk configured with ssid mywrouter
and key mywrouter_key (13 chars needed for wpa) we can use the following configuration.

   iface wlan0 inet dhcp
   wpa-driver wext
   wpa-ssid mywrouter
   wpa-psk mywrouter_key

Be sure to disable reading from everyone to your /etc/network/interfaces. A better approach would be to store it here encrypted
  chmod 600 /etc/network/interfaces


To monitor use knemo and kwifimanager

===== Πηγές =====
  * https://ostechnix.com/connect-and-disconnect-wifi-from-commandline-in-linux/
  *