Date: Thu, 19 Sep 1996 12:29:44 -0700 (MST) From: Terry Lambert <terry@lambert.org> To: dg@Root.COM Cc: rohit@cs.UMD.EDU, freebsd-hackers@freebsd.org Subject: Re: Giant Sized Ethernet Packets Message-ID: <199609191929.MAA01280@phaeton.artisoft.com> In-Reply-To: <199609190350.UAA01225@root.com> from "David Greenman" at Sep 18, 96 08:50:52 pm
next in thread | previous in thread | raw e-mail | index | archive | help
> >I was wondering if it is possible to send giant sized ethernet packets (>1500 > >bytes say 1550) using the current 'de' driver for the SMC 10/100 DEC 21140 > >cards. > > No. > > The answer to this is complicated, but it basically ends up being "no". > I just spent about 15 minutes looking over the DC21140 hardware reference > manual. It appears that the chip can except larger frames, but it signals > an error condition when this occurs, so I don't think you could do this > as a normal mode of operation. I would find this suprising, since it would imply that DEC's cards can't run DECNet (which has a nasty habit of shoving huge frames around). I believe huge frames are technically illegal (according to Xerox), so you should epect that there are hardware limitations which will be biting you somewhere. This doesn't stop DEC from using them, though, so I suspect any card capable of DECNet/LAT/MOP/etc. *should* be physically capable of supporting it. AMD LANCE-based cards should have no problem (except, as you note, potentially in the driver). Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199609191929.MAA01280>