I just dual-booted windows 7 with Debian 7, during the installation it said the wifi firmware was missing so I installed without an internet connection, after the installation I got my LAN cable to install various programs but now i'm having problems configuring the wifi connection, on the windows partition wifi works fine.So first thing I did was install the module for my wifi card, which is:  Intel Centrino Advanced-N 6205 I did it by installing iwlwifi on apt-get.After that it recognized my card, I think, because I could scan for the network:root@debian:/home/user# iwlist wlan0 scanwlan0     Scan completed :          Cell 01 - Address: 7A:B6:86:83:0A:08                    Channel:1                    Frequency:2.412 GHz (Channel 1)                    Quality=48/70  Signal level=-62 dBm                      Encryption key:on                    ESSID:NETWORK                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 9 Mb/s                              18 Mb/s; 36 Mb/s; 54 Mb/s                    Bit Rates:6 Mb/s; 12 Mb/s; 24 Mb/s; 48 Mb/s                    Mode:Master                    Extra:tsf=00000008c098b443                    Extra: Last beacon: 2952ms ago                    IE: Unknown: 00074E4554574F524B                    IE: Unknown: 010882848B961224486C                    IE: Unknown: 030101                    IE: Unknown: 2A0100                    IE: Unknown: 32040C183060                    IE: Unknown: DD180050F2020101000003A4000027A4000042435E0062322F00                    IE: Unknown: 0B05010045127A                    IE: Unknown: DD07000C4304000000                    IE: Unknown: 0706434120010D10I then installed iw to try to connect to the network:root@debian:/home/user# iw dev wlan0 linkConnected to 7a:b6:86:83:0a:08 (on wlan0)    SSID: NETWORK    freq: 2412    RX: 33045 bytes (536 packets)    TX: 1232 bytes (17 packets)    signal: -59 dBm    tx bitrate: 1.0 MBit/s    bss flags:  short-preamble short-slot-time    dtim period:    0    beacon int: 100It says i'm connected to the router, but I still don't have internet access.Some more output:ifconfig:root@debian:/home/user# ifconfigeth0      Link encap:Ethernet  HWaddr 3c:d9:2b:25:51:cb            inet addr:192.168.1.72  Bcast:192.168.1.255  Mask:255.255.255.0          inet6 addr: fe80::3ed9:2bff:fe25:51cb/64 Scope:Link          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1          RX packets:101484 errors:0 dropped:0 overruns:0 frame:0          TX packets:59551 errors:0 dropped:0 overruns:0 carrier:0          collisions:0 txqueuelen:1000           RX bytes:139315514 (132.8 MiB)  TX bytes:5061083 (4.8 MiB)          Interrupt:20 Memory:d1500000-d1520000 lo        Link encap:Local Loopback            inet addr:127.0.0.1  Mask:255.0.0.0          inet6 addr: ::1/128 Scope:Host          UP LOOPBACK RUNNING  MTU:16436  Metric:1          RX packets:343 errors:0 dropped:0 overruns:0 frame:0          TX packets:343 errors:0 dropped:0 overruns:0 carrier:0          collisions:0 txqueuelen:0           RX bytes:30800 (30.0 KiB)  TX bytes:30800 (30.0 KiB)wlan0     Link encap:Ethernet  HWaddr a0:88:b4:85:f5:cc            inet addr:192.168.1.74  Bcast:192.168.1.255  Mask:255.255.255.0          inet6 addr: fe80::a288:b4ff:fe85:f5cc/64 Scope:Link          UP BROADCAST MULTICAST  MTU:1500  Metric:1          RX packets:0 errors:0 dropped:0 overruns:0 frame:0          TX packets:297 errors:0 dropped:0 overruns:0 carrier:0          collisions:0 txqueuelen:1000           RX bytes:0 (0.0 B)  TX bytes:26754 (26.1 KiB)EDIT:root@debian:/home/user# ping 192.168.1.1PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.64 bytes from 192.168.1.1: icmp_req=1 ttl=64 time=1884 ms64 bytes from 192.168.1.1: icmp_req=2 ttl=64 time=876 ms64 bytes from 192.168.1.1: icmp_req=3 ttl=64 time=0.813 ms64 bytes from 192.168.1.1: icmp_req=4 ttl=64 time=0.814 ms64 bytes from 192.168.1.1: icmp_req=5 ttl=64 time=0.845 ms64 bytes from 192.168.1.1: icmp_req=6 ttl=64 time=0.738 ms64 bytes from 192.168.1.1: icmp_req=7 ttl=64 time=0.737 ms64 bytes from 192.168.1.1: icmp_req=8 ttl=64 time=0.752 ms64 bytes from 192.168.1.1: icmp_req=9 ttl=64 time=0.830 ms64 bytes from 192.168.1.1: icmp_req=10 ttl=64 time=0.762 ms64 bytes from 192.168.1.1: icmp_req=11 ttl=64 time=0.768 ms64 bytes from 192.168.1.1: icmp_req=12 ttl=64 time=0.748 ms64 bytes from 192.168.1.1: icmp_req=13 ttl=64 time=0.784 ms64 bytes from 192.168.1.1: icmp_req=14 ttl=64 time=0.743 ms^C--- 192.168.1.1 ping statistics ---14 packets transmitted, 14 received, 0% packet loss, time 13006msrtt min/avg/max/mdev = 0.737/197.826/1884.227/518.915 ms, pipe 2root@debian:/home/user# ping 8.8.8.8connect: Network is unreachableI also noted I'm not getting an inet address when i connect to the router, only after i type dhclient wlan0:root@debian:/home/user# dhclient wlan0PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.--- 192.168.1.1 ping statistics ---1 packets transmitted, 1 received, 0% packet loss, time 0msrtt min/avg/max/mdev = 0.984/0.984/0.984/0.000 msI do get an inet address. But still no internet, moreover, after getting the inet address pinging the router will output errors:root@debian:/home/user# ping 192.168.1.1PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.From 192.168.1.74 icmp_seq=2 Destination Host UnreachableFrom 192.168.1.74 icmp_seq=5 Destination Host UnreachableFrom 192.168.1.74 icmp_seq=8 Destination Host UnreachableFrom 192.168.1.74 icmp_seq=17 Destination Host Unreachable^C--- 192.168.1.1 ping statistics ---20 packets transmitted, 0 received, +4 errors, 100% packet loss, time 19120msEDIT 2:root@debian:/home/user# ip route192.168.1.0/24 dev eth0  proto kernel  scope link  src 192.168.1.72 192.168.1.0/24 dev wlan0  proto kernel  scope link  src 192.168.1.74 root@debian:/home/user# routeKernel IP routing tableDestination     Gateway         Genmask         Flags Metric Ref    Use Iface192.168.1.0     *               255.255.255.0   U     0      0        0 eth0192.168.1.0     *               255.255.255.0   U     0      0        0 wlan0EDIT 3:Currently can't connect to the network at all:root@debian:/home/user# ifconfig wlan0 uproot@debian:/home/user# iw dev wlan0 connect NETWORK keys 1:passwordroot@debian:/home/user# iw dev wlan0 linkNot connected.I can still scan for the network though. 
Wifi not working
debian;wifi;dhcp;internet
You need to add the default route for your network.  This is the 'catch-all' route that is used in the absence of a better one.The command to add a default route is either:route add default gw 192.168.1.1or:ip route add default via 192.168.1.1The above will not be permanent though.To make it permanent, either add it to the network scripts in /etc/network/interfaces or use NetworkManager.