I switched to kernel 3.14.1-trusty, and the problem is fixed. Credit goes to this AskUbuntu question:
http://askubuntu.com/questions/409007/why-doesnt-system-monitor-show- activity-over-ethernet-connections -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-system-monitor in Ubuntu. https://bugs.launchpad.net/bugs/1241894 Title: Network History no longer works in System Monitor since 13.10 Status in gnome-system-monitor package in Ubuntu: Confirmed Bug description: The graph for Network History in Resources tab does not update. Neither does the received and sent data relating to Network History get updated. All the data is just stuck at 0. This started happening after an upgrade to 13.10 from 13.04. It worked perfectly well on 13.04. ProblemType: Bug DistroRelease: Ubuntu 13.10 Package: gnome-system-monitor 3.8.2.1-2 ProcVersionSignature: Ubuntu 3.11.0-12.19-generic 3.11.3 Uname: Linux 3.11.0-12-generic i686 ApportVersion: 2.12.5-0ubuntu2 Architecture: i386 Date: Sat Oct 19 06:39:18 2013 InstallationDate: Installed on 2013-07-06 (104 days ago) InstallationMedia: This MarkForUpload: True SourcePackage: gnome-system-monitor UpgradeStatus: Upgraded to saucy on 2013-10-18 (0 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-system-monitor/+bug/1241894/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
