Wifi connects, can't ping router or external, since 12.04

[m0116815]

Prophetic words... it has indeed come back

$ cat /etc/lsb-release; uname -a
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=12.04
DISTRIB_CODENAME=precise
DISTRIB_DESCRIPTION="Ubuntu 12.04 LTS"
Linux Rogue 3.2.0-24-generic #39-Ubuntu SMP Mon May 21 16:52:17 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
$ lspci -nnk | grep -iA2 net
00:19.0 Ethernet controller [0200]: Intel Corporation 82579LM Gigabit Network Connection [8086:1502] (rev 04)
	Subsystem: Dell Device [1028:04a9]
	Kernel driver in use: e1000e
--
02:00.0 Network controller [0280]: Intel Corporation Centrino Advanced-N 6205 [8086:0082] (rev 34)
	Subsystem: Intel Corporation Centrino Advanced-N 6205 AGN [8086:1321]
	Kernel driver in use: iwlwifi


$ lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 003: ID 0a5c:5800 Broadcom Corp. BCM5880 Secure Applications Processor


$ iwconfig
lo        no wireless extensions.

wlan0     IEEE 802.11abgn  ESSID:"Graymalkin"  
          Mode:Managed  Frequency:2.412 GHz  Access Point: 08:86:3B:B6:3F:E4   
          Bit Rate=65 Mb/s   Tx-Power=15 dBm   
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Power Management:on
          Link Quality=70/70  Signal level=-20 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:36  Invalid misc:3   Missed beacon:0

eth0      no wireless extensions.


$ rfkill list all
1: dell-wifi: Wireless LAN
	Soft blocked: no
	Hard blocked: no
2: dell-bluetooth: Bluetooth
	Soft blocked: yes
	Hard blocked: no
3: phy0: Wireless LAN
	Soft blocked: no
	Hard blocked: no

[m0116815]

I was able to disable the 11n mode and now the wireless works. Interestingly, after rebooting the wireless still worked, even though the disabling did not persist. This is beginning to feel like a router issue.

[wildmanne39]

Hi m0116815, please do:

gksudo gedit /etc/modprobe.d/iwlwifi.conf

Add one line:

options iwlwifi 11n_disable=1

Then:

gksudo gedit /etc/pm/power.d/wireless

(this will create or edit a configuration file that will override the default powermanagement behavior) and enter the following:

#!/bin/sh

/sbin/iwconfig wlan0 power off

above exit0, then save gedit, close and reboot.
Thanks

[trichome tetrahydron]

Hi, please try:

sudo ifconfig wlan0 down
sudo rmmod -f iwlwifi
sudo modprobe iwlwifi 11n_disable=1
sudo ifconfig wlan0 up

does it connect now? this is just for testing so do not reboot if it works we will need to make it permanent.
Thanks

thank you so much to user RobertSwipe. I am running lubuntu 12.04 and was having the same irritating problem! I tried all manner of things, turns out it was not a problem with dns as many other threads led me to believe - your commands worked perfectly. Could you explain why they worked? what is 11n_disable=1?

[wildmanne39]

Hi, it disables N speed because some drivers do not handle N speed well.
Thanks

[ReetP]

Hi, it disables N speed because some drivers do not handle N speed well.
Thanks

Have had the same problem with an Acer Aspire One D255 N550 using iwlwifi with a Draytek 2820 router. I guess there is a bug with the driver someplace.

The odd thing is that everything looked OK apart from the ping to a local IP address which just sits there and does nothing.

Changing the particular router to just 'b/g' and no 'n' solved it for me in the short term.

[aldeirm2]

Hi,

I am having the same issue, i tried the last suggestion and it has improved my situation, now I can ping my router and other devices connected to the same router but still have no access to the internet or cant ping ip's outside my network.

Any one can help please?