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I have a desktop which dual-boots to Kubuntu 14.04 by preference, or Windows 7. My wife has an iMac desktop and we have various Wi-Fi tablets and phones. We have a Technicolor tg582n router to which the desktops are connected by ethernet through TP-Link PA211 "Powerline" Home plugs; we use two TP-Link WPA271 Home plugs for Wi-Fi in the parts of the house not reached by the TG582n.

I recently reset the five TP-link devices because our broadband kept dropping out. They now have factory default settings except for a password for security on the Wi-Fi devices. We now have broadband on all devices (including my desktop on Windows) at about 16Mbps, the speed advertised by our ISP and ample for our use. There is one exception: whereas I had an excellent Ethernet connection on Kubuntu before, I now need to use a Wi-Fi dongle and it is noticeably slower. Any help much appreciated. To make this clear, I only need the dongle because Kubuntu won't now connect by Ethernet, as it did before I reset the home plugs. Before, my desktop connected by ethernet in Windows and Kubuntu; now only Windows connects by Ethernet.

The dongle is OK, the problem is that WiFi is always slower than Ethernet.

Edit: Now getting 14Mbps download but still stuck on @Fabby's stage 4. Output of ifconfig:

WGCman@WGCman-XXXX-D3:~$ 

sudo ethtool --change eth0 speed 100 duplex full autoneg off

[sudo] password for WGCman: 

 WGCman@WGCman-XXXX-D3:~$ ifconfig

eth0      Link encap:Ethernet  HWaddr fc:aa:14:06:xx:xx  
      inet addr:192.168.1.70  Bcast:192.168.1.255  Mask:255.255.255.0
      UP BROADCAST RUNNING MULTICAST  MTU:100  Metric:1
      RX packets:88065 errors:0 dropped:0 overruns:0 frame:0
      TX packets:46875 errors:0 dropped:0 overruns:0 carrier:0
      collisions:0 txqueuelen:1000 
      RX bytes:22091647 (22.0 MB)  TX bytes:3947548 (3.9 MB)

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:1928 errors:0 dropped:0 overruns:0 frame:0
      TX packets:1928 errors:0 dropped:0 overruns:0 carrier:0
      collisions:0 txqueuelen:0 
      RX bytes:283489 (283.4 KB)  TX bytes:283489 (283.4 KB)
WGCman
  • 347

1 Answers1

3

You should turn off auto-negotiation on the machine and fix the network speed to the highest level that the Network Interface Card (NIC) can sustain on your powerline adapter.

Start with 10Mbps, half duplex and work upwards to 10Mbps FD, 100Mbps HD, ... until the problem starts. Then go down one notch and leave it at that speed.

First, install ethtool (if already installed you will just get a warning that the latest version is already installed)

sudo apt-get install ethtool

Now:

  1. Type the following command (and test them one by one)

    sudo ethtool --change eth0 speed xxx duplex yyy autoneg off

    where xxx = 10, 100 or 1000 and yyy = half or full.

    So start with 10 half, 10 full, 100 half, ...

  2. Do an ifconfig to check whether you got an IP address.

  3. Go back to 1 until it stops working and use the previous values that still worked to:

  4. To make the change permanent, execute the following command:

    sudo nano /etc/network/interfaces

    and type at the pre-up section:

    pre-up /usr/sbin/ethtool --change eth0 speed xxx duplex yyy autoneg off
Fabby
  • 35,017