Gigabit Ethernet w/Jumbo Frames

[Erik Trulsson]

On Tue, Jun 26, 2007 at 11:12:23PM -0700, John-Mark Gurney wrote:
> george+freebsd at m5p.com wrote this message on Tue, Jun 26, 2007 at 17:33 -0700:
> > I'm having poor luck trying to use NFS over a gigabit ethernet using
> > jumbo frames.  By all indications, my switch (Netgear GS608) forwards
> > jumbo frames with no difficulty, but my Realtek 8169-based cards seem
> 
> Are you sure?  I just tried w/ my GS608 again, and it still doesn't
> pass jumbo frames...  I specifically bought a second switch, an SMC
> 8508T so that I could work on jumbo frame support...  I took my MBP
> to the SMC and verified that I could ping 5k packets w/o fragmentation
> between the two (MBP and a FreeBSD-current box w/ an em card) boxes,
> and then took my MBP to the Netgear, and the remote box would not see
> the large pings...
> 
> I just checked Netgear's website, and they do list Jumbo Frame support..
> Either I have an old switch and newer ones support it, or they depend
> upon that most people can't figure out to make jumbo frames work
> reliabily and depend upon people just using 1500 byte frames...

There are (at least) two different versions of the Netgear GS608 (and some
other Netgear switches.) The older ones do not support Jumbo Frames, while
the newer ones are supposed to do it.  See

http://kbserver.netgear.com/inquira/default.asp?ui_mode=answer&prior_transaction_id=5016326&action_code=5&highlight_info=16778279,200,201&turl=http%3A%2F%2Fkbserver.netgear.com%2Fkb_web_files%2Fn101624.asp&answer_id=6141591#__highlight

for some more information on the different versions of some Netgear
switches.


-- 
<Insert your favourite quote here.>
Erik Trulsson
ertr1013 at student.uu.se