I am new to Ubuntu 14.04 LTS and I just installed it today on my Lenovo G50-70 laptop. Before marking this as duplicate, please hear me out. I have read countless posts on this issue, but none have been able to help me. I am having an issue with the WiFi that I didn't have with Windows 10, my previous OS. This issue started since installing Ubuntu when I was trying to install updates. The Internet on my laptop goes out randomly, but all other computers are fine so it can't be my router. Sometimes it stops working after a minute after reboot and sometimes an hour. It's random as to when it will stop working and once it's gone, it doesn't come back unless I reboot. I have 2 Windows 10 machines and another Ubuntu 14.04 machine that my brother runs that is fine. The Internet issue I am facing resolves upon reboot, but it occurs again randomly when I'm browsing and is not fixed by enabling/disabling WiFi or disconnecting/reconnecting. I have to restart the computer to fix the wifi. I ran the command dmesg before the Internet could go out again and got the result. I am unable to post it on here since there's a character limit, but I have the result in a text file. I have also tried to change my ipv6 settings to Link-Local Only, but that didn't resolve the issue. Also, the WiFi icon says that my Internet is fine, but it isn't. Pinging in the terminal also does not work when the Internet is gone, even though the WiFi icon is still active.

After the Internet went out, I ran the command lcpci -v and got:

00:00.0 Host bridge: Intel Corporation Haswell-ULT DRAM Controller (rev 0b)
    Subsystem: Lenovo Device 3978
    Flags: bus master, fast devsel, latency 0
    Capabilities: <access denied>

00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated Graphics Controller (rev 0b) (prog-if 00 [VGA controller])
    Subsystem: Lenovo Device 380c
    Flags: bus master, fast devsel, latency 0, IRQ 47
    Memory at c0000000 (64-bit, non-prefetchable) [size=4M]
    Memory at b0000000 (64-bit, prefetchable) [size=256M]
    I/O ports at 5000 [size=64]
    Expansion ROM at <unassigned> [disabled]
    Capabilities: <access denied>
    Kernel driver in use: i915

00:03.0 Audio device: Intel Corporation Haswell-ULT HD Audio Controller (rev 0b)
    Subsystem: Lenovo Device 3978
    Flags: bus master, fast devsel, latency 0, IRQ 48
    Memory at c0610000 (64-bit, non-prefetchable) [size=16K]
    Capabilities: <access denied>
    Kernel driver in use: snd_hda_intel

00:14.0 USB controller: Intel Corporation Lynx Point-LP USB xHCI HC (rev 04) (prog-if 30 [XHCI])
    Subsystem: Lenovo Device 3978
    Flags: bus master, medium devsel, latency 0, IRQ 42
    Memory at c0600000 (64-bit, non-prefetchable) [size=64K]
    Capabilities: <access denied>
    Kernel driver in use: xhci_hcd

00:16.0 Communication controller: Intel Corporation Lynx Point-LP HECI #0 (rev 04)
    Subsystem: Lenovo Device 3978
    Flags: bus master, fast devsel, latency 0, IRQ 45
    Memory at c0618000 (64-bit, non-prefetchable) [size=32]
    Capabilities: <access denied>
    Kernel driver in use: mei_me

00:1b.0 Audio device: Intel Corporation Lynx Point-LP HD Audio Controller (rev 04)
    Subsystem: Lenovo Device 3978
    Flags: bus master, fast devsel, latency 0, IRQ 46
    Memory at c0614000 (64-bit, non-prefetchable) [size=16K]
    Capabilities: <access denied>
    Kernel driver in use: snd_hda_intel

00:1c.0 PCI bridge: Intel Corporation Lynx Point-LP PCI Express Root Port 3 (rev e4) (prog-if 00 [Normal decode])
    Flags: bus master, fast devsel, latency 0
    Bus: primary=00, secondary=01, subordinate=01, sec-latency=0
    I/O behind bridge: 00004000-00004fff
    Memory behind bridge: c0500000-c05fffff
    Capabilities: <access denied>
    Kernel driver in use: pcieport

00:1c.3 PCI bridge: Intel Corporation Lynx Point-LP PCI Express Root Port 4 (rev e4) (prog-if 00 [Normal decode])
    Flags: bus master, fast devsel, latency 0
    Bus: primary=00, secondary=02, subordinate=02, sec-latency=0
    I/O behind bridge: 00003000-00003fff
    Memory behind bridge: c0400000-c04fffff
    Capabilities: <access denied>
    Kernel driver in use: pcieport

00:1d.0 USB controller: Intel Corporation Lynx Point-LP USB EHCI #1 (rev 04) (prog-if 20 [EHCI])
    Subsystem: Lenovo Device 3978
    Flags: bus master, medium devsel, latency 0, IRQ 23
    Memory at c061c000 (32-bit, non-prefetchable) [size=1K]
    Capabilities: <access denied>
    Kernel driver in use: ehci-pci

00:1f.0 ISA bridge: Intel Corporation Lynx Point-LP LPC Controller (rev 04)
    Subsystem: Lenovo Device 3978
    Flags: bus master, medium devsel, latency 0
    Capabilities: <access denied>
    Kernel driver in use: lpc_ich

00:1f.2 SATA controller: Intel Corporation Lynx Point-LP SATA Controller 1 [AHCI mode] (rev 04) (prog-if 01 [AHCI 1.0])
    Subsystem: Lenovo Device 3978
    Flags: bus master, 66MHz, medium devsel, latency 0, IRQ 43
    I/O ports at 5088 [size=8]
    I/O ports at 5094 [size=4]
    I/O ports at 5080 [size=8]
    I/O ports at 5090 [size=4]
    I/O ports at 5060 [size=32]
    Memory at c061b000 (32-bit, non-prefetchable) [size=2K]
    Capabilities: <access denied>
    Kernel driver in use: ahci

00:1f.3 SMBus: Intel Corporation Lynx Point-LP SMBus Controller (rev 04)
    Subsystem: Lenovo Device 3978
    Flags: medium devsel
    Memory at c0619000 (64-bit, non-prefetchable) [size=256]
    I/O ports at 5040 [size=32]

01:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 10)
    Subsystem: Lenovo Device 380a
    Flags: bus master, fast devsel, latency 0, IRQ 44
    I/O ports at 4000 [size=256]
    Memory at c0504000 (64-bit, non-prefetchable) [size=4K]
    Memory at c0500000 (64-bit, non-prefetchable) [size=16K]
    Capabilities: <access denied>
    Kernel driver in use: r8169

02:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter
    Subsystem: Lenovo Device b736
    Flags: bus master, fast devsel, latency 0, IRQ 19
    I/O ports at 3000 [size=256]
    Memory at c0400000 (64-bit, non-prefetchable) [size=16K]
    Capabilities: <access denied>
    Kernel driver in use: rtl8723be

I then ran ifconfig and got:

eth0      Link encap:Ethernet  HWaddr 68:f7:28:18:33:e0  
          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)

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:1392 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1392 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:125457 (125.4 KB)  TX bytes:125457 (125.4 KB)

wlan0     Link encap:Ethernet  HWaddr c0:38:96:12:bd:c7  
          inet addr:192.168.1.129  Bcast:192.168.1.255 Mask:255.255.255.0
          inet6 addr: fe80::c238:96ff:fe12:bdc7/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:4186 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4472 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:4124758 (4.1 MB)  TX bytes:810905 (810.9 KB)

I would greatly appreciate if someone could help me on this issue. If you need the results for dmesg, please let me know so that I can post it. Thank you for your time.

  • Is it just me or is this a more comprehensive duplicate of the question below? askubuntu.com/questions/667513/… – TheWanderer Aug 30 '15 at 23:31
  • @Zacharee1 I was not aware of that post as it never showed up in any searches that I conducted. Nonetheless, neither post has an answer. – Joffrey Baratheon Aug 30 '15 at 23:33
  • That wasn't a duplicate report. I just thought it interesting that two people had the exact problem at the same time. Have you tried reinstalling the network drivers or running sudo apt-get update and sudo apt-get upgrade? – TheWanderer Aug 30 '15 at 23:35
  • 1
    Just a workaround, but upgrading to 15.04 might fix it. If not, it's probably a hardware issue. – TheWanderer Aug 30 '15 at 23:38
  • 1
    Well that definitely points to it being a driver bug with Ubuntu, though it could still have something to do with your specific hardware. Sorry if I suggest something you've already disproved or tried. I'm just a little busy for the time being. – TheWanderer Aug 31 '15 at 1:17
up vote 0 down vote accepted

I found a solution, but it is not THE solution. According to my searches on this issue, for some odd reason, majority of the machines having this problem are by Lenovo. I'm not sure if this issue is a result of hardware conflicts or what, but I "fixed" the issue by installing a fresh copy of 15.04 and it is working perfectly.

The machine started off at Windows 8 and was perfect for 8.1 and 10. When I installed a fresh copy of 14.04, I experienced the issue I detailed above. I experienced the same issue at 14.10. When I reinstalled a fresh copy of Windows 8.1, the laptop functioned perfectly. When I tried 14.04 again, same issue. This leads me to believe that there is some sort of problem with what's being supported in 14.04. When I fresh installed 15.04, everything ran perfectly.

So if you're having this issue and you absolutely cannot figure out how to fix this problem, I recommend trying out 15.04. Yes, it's not a solution to the problem since I, myself, wanted 14.04 LTS, but at least with this method, your laptop isn't useless.

For now, I will mark this as the best answer.

  • This bug is probably already reported. See search results at bugs.launchpad.net/… and find the most appropriate one for you. Then add yourself as affected by the bug. thus the bug gets more attention. – user68186 Aug 31 '15 at 18:04
  • Interesting, upgrading to 15.04 didn't work for me. – TheNumberOne Sep 4 '15 at 15:24
  • @TheNumberOne Did you rule out hardware malfunction? Was it a fresh install? – Joffrey Baratheon Sep 4 '15 at 18:47
  • @JoffreyBaratheon I did rule out hardware malfunction. However, I did use apt to upgrade my system instead of doing a fresh install. I found that switching to WEP encryption fixes the problem. – TheNumberOne Sep 4 '15 at 19:36

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