Kali Linux Wireless Card not working

Question

I preformed a fresh install of Kali Linux on my laptop,so now the only operating system available is Kali Linux.

Here's my problem: My laptop cannot connect to the Internet through the already built-in wireless card. My laptop wireless card is: Intel Corporation Centrino Advanced-N 6200 2x2 AGN and although the system says that it using the kernal drivers for iwlwifi there is still no wireless Internet connection.

I tried changing the interfaces file under /etc/network/interfaces and added:
# The primary network interfaces
auto wlan0
allow-hotplug wlan0
iface wlan0 inet dhcp
Still no luck.
Here's the ifconfig details:

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.77  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::223:18ff:febe:ab8e  prefixlen 64  scopeid 0x20<link>
        ether 00:23:18:be:ab:8e  txqueuelen 1000  (Ethernet)
        RX packets 27689  bytes 27448393 (26.1 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 15299  bytes 1495734 (1.4 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device interrupt 20  memory 0xd4600000-d4620000  

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1  (Local Loopback)
        RX packets 2460  bytes 187820 (183.4 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2460  bytes 187820 (183.4 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlan0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether 00:27:10:94:a8:3c  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

Here's the iwconfig details:

lo        no wireless extensions.

wlan0     IEEE 802.11abgn  ESSID:"ATT653"  
          Mode:Managed  Access Point: Not-Associated   Tx-Power=15 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off

eth0      no wireless extensions.

NOTE: For the ESSID, I manually added "ATT653" using

ifconfig wlan0 up
iwconfig wlan0 essid "ATT653"
dhclient wlan0

This didn't work because my network is WPA2 encrypted.
Here's the wireless card information:

root@kali:~# lspci
02:00.0 Network controller: Intel Corporation Centrino Advanced-N 6200 (rev 35)

and

root@kali:~# lspci -vq
02:00.0 Network controller: Intel Corporation Centrino Advanced-N 6200 (rev 35)
    Subsystem: Intel Corporation Centrino Advanced-N 6200 2x2 AGN
    Flags: bus master, fast devsel, latency 0, IRQ 29
    Memory at d4400000 (64-bit, non-prefetchable) [size=8K]
    Capabilities: [c8] Power Management version 3
    Capabilities: [d0] MSI: Enable+ Count=1/1 Maskable- 64bit+
    Capabilities: [e0] Express Endpoint, MSI 00
    Capabilities: [100] Advanced Error Reporting
    Capabilities: [140] Device Serial Number 00-27-10-ff-ff-94-a8-3c
    Kernel driver in use: iwlwifi
    Kernel modules: iwlwifi

Answer 1

The way to connect to a WPA2-PSK network manually is the following:

wpa_passphrase NetworkBSSID NetworkPassword > somefile.txt
ip link set dev wlan0 down
ip addr flush dev wlan0
pkill -9 dhclient
pkill -9 wpa_supplicant
ip link set dev wlan0 up
wpa_supplicant -B -Dnl80211 -i wlan0 -c somefile.txt 
dhclient -v wlan0

After this exchange, make sure that your DHCP server has passed you both a default gateway (ip route show | grep default) and suitable name servers (cat /etc/resolv.conf). If not, you need to correct this:

ip route add default via IP.Address.Of.YourGW
echo "nameserver 8.8.8.8" >> /etc/resolv.conf
echo "nameserver 8.8.4.4" >> /etc/resolv.conf

Of the bunch of 8 commands above, the first command is needed only once, of course. The following five commands clean up after previous connection attempts. The call to wpa_supplicant is what you really missed. The use of the nl80211 driver is made possible by the fact that iwlwifi is a fully 80211-compliant driver, hence you do not need to use the old driver, wext.

Please do not be confused: in the wpa_supplicant call, you should not use the name of your kernel-space driver, iwlwifi: you must use the name of your user-space driver, nl80211.

Lastly, the commands you use, ifconfig and iwconfig, are obsolete, pls use ip instead.