cat /etc/network/interfaces:
auto lo
iface lo inet loopback

iwconfig: 
lo        no wireless extensions.

eth0      no wireless extensions.

wlan0     IEEE 802.11abgn  ESSID:off/any  
          Mode:Managed  Access Point: Not-Associated   Tx-Power=off   
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Power Management:on

ifconfig:
eth0      Link encap:Ethernet  Hardware Adresse f0:de:f1:63:bb:13  
          UP BROADCAST MULTICAST  MTU:1500  Metrik:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          Kollisionen:0 Sendewarteschlangenlänge:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
          Interrupt:20 Speicher:f2400000-f2420000 

lo        Link encap:Lokale Schleife  
          inet Adresse:127.0.0.1  Maske:255.0.0.0
          inet6-Adresse: ::1/128 Gültigkeitsbereich:Maschine
          UP LOOPBACK RUNNING  MTU:16436  Metrik:1
          RX packets:4610 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4610 errors:0 dropped:0 overruns:0 carrier:0
          Kollisionen:0 Sendewarteschlangenlänge:0 
          RX bytes:362972 (362.9 KB)  TX bytes:362972 (362.9 KB)

lspci -nn | grep Network:
00:19.0 Ethernet controller [0200]: Intel Corporation 82577LM Gigabit Network Connection [8086:10ea] (rev 06)
03:00.0 Network controller [0280]: Intel Corporation Centrino Ultimate-N 6300 [8086:4238] (rev 35)

nm-tool:
NetworkManager Tool

State: disconnected

- Device: eth0 -----------------------------------------------------------------
  Type:              Wired
  Driver:            e1000e
  State:             unavailable
  Default:           no
  HW Address:        F0:DE:F1:63:BB:13

  Capabilities:
    Carrier Detect:  yes

  Wired Properties
    Carrier:         off


- Device: wlan0 ----------------------------------------------------------------
  Type:              802.11 WiFi
  Driver:            iwlagn
  State:             unavailable
  Default:           no
  HW Address:        00:24:D7:DF:6A:B4

  Capabilities:

  Wireless Properties
    WEP Encryption:  yes
    WPA Encryption:  yes
    WPA2 Encryption: yes

  Wireless Access Points

sudo lshw -C network
  *-network               
       description: Ethernet interface
       product: 82577LM Gigabit Network Connection
       vendor: Intel Corporation
       physical id: 19
       bus info: pci@0000:00:19.0
       logical name: eth0
       version: 06
       serial: f0:de:f1:63:bb:13
       capacity: 1Gbit/s
       width: 32 bits
       clock: 33MHz
       capabilities: pm msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=1.3.10-k2 firmware=0.12-1 latency=0 link=no multicast=yes port=twisted pair
       resources: irq:41 memory:f2400000-f241ffff memory:f2425000-f2425fff ioport:1820(size=32)
  *-network DISABLED
       description: Wireless interface
       product: Centrino Ultimate-N 6300
       vendor: Intel Corporation
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: wlan0
       version: 35
       serial: 00:24:d7:df:6a:b4
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=iwlagn driverversion=3.0.0-15-generic-pae firmware=9.221.4.1 build 25532 latency=0 link=no multicast=yes wireless=IEEE 802.11abgn
       resources: irq:44 memory:f2000000-f2001fff


less /var/log/syslog | grep wla
Feb  7 21:29:07 R8DY69X kernel: [   12.361527] iwlagn: Intel(R) Wireless WiFi Link AGN driver for Linux, in-tree:
Feb  7 21:29:07 R8DY69X kernel: [   12.361532] iwlagn: Copyright(c) 2003-2011 Intel Corporation
Feb  7 21:29:07 R8DY69X kernel: [   12.361612] iwlagn 0000:03:00.0: PCI INT A -> GSI 17 (level, low) -> IRQ 17
Feb  7 21:29:07 R8DY69X kernel: [   12.361623] iwlagn 0000:03:00.0: setting latency timer to 64
Feb  7 21:29:07 R8DY69X kernel: [   12.361656] iwlagn 0000:03:00.0: Detected Intel(R) Centrino(R) Ultimate-N 6300 AGN, REV=0x74
Feb  7 21:29:07 R8DY69X kernel: [   12.378076] iwlagn 0000:03:00.0: device EEPROM VER=0x436, CALIB=0x6
Feb  7 21:29:07 R8DY69X kernel: [   12.378080] iwlagn 0000:03:00.0: Device SKU: 0Xb
Feb  7 21:29:07 R8DY69X kernel: [   12.378082] iwlagn 0000:03:00.0: Valid Tx ant: 0X7, Valid Rx ant: 0X7
Feb  7 21:29:07 R8DY69X kernel: [   12.379133] iwlagn 0000:03:00.0: Tunable channels: 13 802.11bg, 24 802.11a channels
Feb  7 21:29:07 R8DY69X kernel: [   12.379217] iwlagn 0000:03:00.0: irq 44 for MSI/MSI-X
Feb  7 21:29:07 R8DY69X kernel: [   12.816972] iwlagn 0000:03:00.0: loaded firmware version 9.221.4.1 build 25532
Feb  7 21:29:07 R8DY69X NetworkManager[940]:    SCPlugin-Ifupdown: devices added (path: /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/net/wlan0, iface: wlan0)
Feb  7 21:29:07 R8DY69X NetworkManager[940]:    SCPlugin-Ifupdown: device added (path: /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/net/wlan0, iface: wlan0): no ifupdown configuration found.
Feb  7 21:29:07 R8DY69X NetworkManager[940]: <info> (wlan0): driver supports SSID scans (scan_capa 0x01).
Feb  7 21:29:07 R8DY69X NetworkManager[940]: <info> (wlan0): new 802.11 WiFi device (driver: 'iwlagn' ifindex: 3)
Feb  7 21:29:07 R8DY69X NetworkManager[940]: <info> (wlan0): exported as /org/freedesktop/NetworkManager/Devices/1
Feb  7 21:29:07 R8DY69X NetworkManager[940]: <info> (wlan0): now managed
Feb  7 21:29:07 R8DY69X NetworkManager[940]: <info> (wlan0): device state change: unmanaged -> unavailable (reason 'managed') [10 20 2]
Feb  7 21:29:07 R8DY69X NetworkManager[940]: <info> (wlan0): bringing up device.
Feb  7 21:29:07 R8DY69X NetworkManager[940]: <info> (wlan0): deactivating device (reason 'managed') [2]