Look for a packet loop on the interface. Use tcpdump on the interface to see if there are excess packets being generated from somewhere. There are numerous things that can blow up a LAN. The most common being that a switch port is wired to loop back into the LAN.
-Matt On Sun, Oct 16, 2016 at 9:17 AM, Justin Sherrill <jus...@shiningsilence.com> wrote: > On Sun, Oct 16, 2016 at 11:49 AM, Richard Nyberg <rnyb...@murmeldjur.se> > wrote: > > Thanks! > > > > Here are some more datapoints. > > I think the only constant at this point is the internal interface on > the DragonFly system. If you hook the em0 interface that's currently > internal on the DragonFly machine up to your Internet link (i.e. > reverse which interface is internal or external), does it still > perform badly? > > If it doesn't work well, then that interface is bad. I'd be > surprised, cause I've seen network ports go bad very rarely, but it's > possible. Plus, I don't have any other ideas. >