Why doesn't System Monitor show activity over ethernet connections?

I have a similar ethernet controller and have the same issue:

$ lspci | grep Ethernet
02:00.0 Ethernet controller: Qualcomm Atheros AR8161 Gigabit Ethernet (rev 10)

This is a bug that affects Ubuntu 13.10 and Ubuntu 14.04. The bug has been fixed in Linux Mainline Kernel v3.14 and later. So, you would need to install the mainline kernel to fix the issue.

Download the latest stable release of Mainline Build from this page. If the folder name doesn't contain the word rc in it, then it's a stable build. As of this writing the stable build is v3.14.1-trusty (this would work for Ubuntu 13.10 as well).

Download the *.deb files based on your architecture. Refer this section on Ubuntu Wiki on what you need to download. Once downloaded, open your terminal, cd to the downloaded directory and run sudo dpkg -i *.deb to install them. Then reboot to check if it works for you.

Note: You won't get automatic updates for this version of kernel. You would need to manually check the download page and install them yourself to remain updated.

• Refer Ubuntu Wiki on Kernel Mainline Builds for more information about them

• Following are the bugs reported on Launchpad in this respect; go and mark that you are also affected by the bug:

  1. Network History no longer works in System Monitor on 13.10
  2. Missing statistics for tx_bytes, tx_packets, rx_bytes and rx_packets since Ubuntu 13.10