On Wed, Mar 26, 2014 at 10:35:43PM -0700, Aaron J. Grier wrote: > (necromancing old threads...) > > On Fri, Nov 08, 2013 at 11:09:59AM -0500, Michael T. Davis wrote: > > Every so often, the NetBSD-6 kernel reports... > > > > Nov 8 09:44:17 fw /netbsd: wm1: discarding oversize frame (len=1518) > > > > It only ever cites wm1 and the length is always 1518. Since the MTU > > for this interface is set to 1500, doesn't this mean that another > > system attached to that interface is generating an invalid packet, > > presumably due to a mis-configuration? > > FWIW I see this on nfe on my sunfire x2200m2. the nfe is attached by a > vlan, but vlan packets are 1504 bytes -- 1518 seems a very strange > number.
I recognize the number, here is how I think it comes about: 6-byte destination MAC + 6-byte source MAC + 2-byte outer ethertype (VLAN) + 2-byte VLAN tag + 2-byte inner ethertype + 1500 MTU = 1518 bytes. Dave -- David Young [email protected] Urbana, IL (217) 721-9981
