Ubuntu: wireless connected but slow


I am connected to the wireless but the speed oscillates a lot, sometimes it does not work at all. A restart usually fixes it, which I find pretty weird.

I know it is not the modem because I have other machines working fine.

can someone give me a clue? here goes a lspci and a iwconfig

thanks in advance

eth0      no wireless extensions.    lo        no wireless extensions.    wlan0     IEEE 802.11abgn  ESSID:"Naboo"              Mode:Managed  Frequency:2.422 GHz  Access Point: 1C:AF:F7:5B:5C:8C               Bit Rate=57.8 Mb/s   Tx-Power=15 dBm               Retry  long limit:7   RTS thr:off   Fragment thr:off            Power Management:off            Link Quality=37/70  Signal level=-73 dBm              Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0            Tx excessive retries:2039  Invalid misc:472   Missed beacon:0  

and also

lspci -nnk | grep -iA2 net  01:00.0 Network controller [0280]: Intel Corporation Centrino Advanced-N 6235 [8086:088e] (rev 24)      Subsystem: Intel Corporation Centrino Advanced-N 6235 AGN [8086:4060]      Kernel driver in use: iwlwifi  --  02:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller [10ec:8168] (rev 06)      Subsystem: Samsung Electronics Co Ltd Device [144d:c0d7]      Kernel driver in use: r8169  


Nice network you got, since you mentioned other systems work without the hiccups you're right to suspect your box.

I had this problem and it was a Fedora post about disabling IPv6 that made the difference and normalized things.

I'd copy that /etc/sysctl.conf before editing it in case it doesn't help and a butchered config is just a new wound.

sudo cp /etc/sysctl.conf /etc/sysclt.conf.BACKED    sudo gedit /etc/sysctl.conf  

and append these lines

net.ipv6.conf.all.disable_ipv6 = 1    net.ipv6.conf.default.disable_ipv6 = 1    net.ipv6.conf.lo.disable_ipv6 = 1  

If you have the courage, you can just cat the file to determine if ipv6 configs are already included and if not, you can cat those lines and skip the gedit

sudo cp /etc/sysctl.conf /etc/sysclt.conf.BACKED    cat /etc/sysctl.conf    echo "net.ipv6.conf.all.disable_ipv6 = 1" | sudo tee -a  /etc/sysctl.conf    echo "net.ipv6.conf.default.disable_ipv6 = 1" | sudo tee -a /etc/sysctl.conf    echo "net.ipv6.conf.lo.disable_ipv6 = 1" | sudo tee -a /etc/sysctl.conf  

dump the config file again to verify the changes took effect and you didn't stomp it

cat /etc/sysctl.conf  

I rebooted to make sure the change was effected and my WiFi behaved as it should.

I hope this makes a difference for you.


Erratic speed on a wireless link is often related to interference. Also it can be caused by another wlan in proximity that is using the same channel. Try changing the transmission channel of your modem/router.

Note:If u also have question or solution just comment us below or mail us on toontricks1994@gmail.com
Next Post »