[dsmithhfx]

I've been having consistent problems with Network Manager after all recent updates (after kernel 3.30-4). It doesn't seem to matter what the updates are, whether they include networking components and/or kernel upgrades.

Each time the same thing happens: after applying the update, NM fails to establish a wired connection on reboot.

Fortunately for me, so far, there is a temporary fix: stop networking (from the top menu bar), open the NM gui applet, delete and recreate the eth device, and restart networking. After doing this, NM successfully establishes a connection immediately and on subsequent reboots, until the next update is applied (again -- so far). YMMV.

The first time it happened I posted a query here (much like yours), and went on to try a bunch of stuff including rolling back iproute to a prior version, and disabling ipv6.

In hindsight, since the problem keeps coming back, I doubt these modifications made any real difference to the underlying issue(s).