I did a fresh install of Ubuntu 14.04 LTS on the harddisk of a Lenovo Y650 Ideapad laptop. The wireless adapter is an Intel PRO/Wireless 5100 AGN [Shiloh].
Initially I could not connect to any wireless networks; however, I could see them. There are no issues when connecting via Ethernet. I was only able to connect to the wireless network by entering this command in the Terminal:
echo "options iwlwifi 11n_disable=1" | sudo tee /etc/modprobe.d/iwlwifi.conf
The speeds are extremely slow and intermittent. When I am able to run a speed test, the ping is good (24 to 26 ms) but the download speeds range from 0.15 to 0.30 Mbps.
iwconfig
eth0 no wireless extensions.
lo no wireless extensions.
wlan0 IEEE 802.11abg ESSID:"PinkRabbit"
Mode:Managed Frequency:2.412 GHz Access Point: E8:40:F2:CD:18:0B
Bit Rate=2 Mb/s Tx-Power=15 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Power Management:off
Link Quality=70/70 Signal level=-26 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:3 Invalid misc:254 Missed beacon:0
ifconfig
eth0 Link encap:Ethernet HWaddr 00:23:5a:d2:70:91
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
Interrupt:17
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:65536 Metric:1
RX packets:171 errors:0 dropped:0 overruns:0 frame:0
TX packets:171 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:15613 (15.6 KB) TX bytes:15613 (15.6 KB)
wlan0 Link encap:Ethernet HWaddr 00:1e:65:3e:0c:48
inet addr:192.168.0.13 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::21e:65ff:fe3e:c48/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:42 errors:0 dropped:0 overruns:0 frame:0
TX packets:96 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:9032 (9.0 KB) TX bytes:16851 (16.8 KB)
nm-tool
NetworkManager Tool
State: connected (global)
- Device: eth0 -----------------------------------------------------------------
Type: Wired
Driver: tg3
State: unavailable
Default: no
HW Address: 00:23:5A:D2:70:91
Capabilities:
Carrier Detect: yes
Wired Properties
Carrier: off
- Device: wlan0 [PinkRabbit] --------------------------------------------------
Type: 802.11 WiFi
Driver: iwlwifi
State: connected
Default: yes
HW Address: 00:1E:65:3E:0C:48
Capabilities:
Speed: 1 Mb/s
Wireless Properties
WEP Encryption: yes
WPA Encryption: yes
WPA2 Encryption: yes
Wireless Access Points (* = current AP)
*PinkRabbit: Infra, E8:40:F2:CD:18:0B, Freq 2412 MHz, Rate 54 Mb/s, Strength 92 WPA WPA2
IPv4 Settings:
Address: 192.168.0.13
Prefix: 24 (255.255.255.0)
Gateway: 192.168.0.1
DNS: 64.71.255.204
DNS: 64.71.255.198
DNS: 8.8.8.8
DNS: 8.8.4.4
Best Answer
I don't know how much relevant this may be, still an Ubuntu newbie, but I had similar problems with my Ralink 5362 card.
The only thing it seemed to work was the following:
There is a bug in the Debian Avahi daemon in Ubuntu. And to resolve this you need to edit the following file
/etc/nsswitch.conf
as follows.Type the following in the command line
This will open the nsswitch.conf file in the text editor. Then simply change the following line
to the below line and save the file.
Reset your internet connection or probably restart your system and your wireless connection should be back on top speed. This worked for me at least.