Date: Thu, 19 Sep 1996 16:38:09 +0000 From: Matt Thomas <matt@lkg.dec.com> To: Terry Lambert <terry@lambert.org> Cc: freebsd-hackers@freebsd.org Subject: Re: Giant Sized Ethernet Packets Message-ID: <199609191638.QAA26304@whydos.lkg.dec.com> In-Reply-To: Your message of "Thu, 19 Sep 1996 12:29:44 MST." <199609191929.MAA01280@phaeton.artisoft.com>
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In <199609191929.MAA01280@phaeton.artisoft.com>, Terry Lambert wrote: > > 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). That is *complete* and *utter* bullsh*t. DECnet uses standard size Ethernet frames. Always has, always will. > 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). Again, no DEC developed protocol uses over-sized Ethernet frames. Why do I know this? Because for the last several years I (as a Digital employee) have owned (and continure to own) all the DECnet specifications. In fact, I implemented most of them as well. -- Matt Thomas Internet: matt@3am-software.com 3am Software Foundry WWW URL: http://www.3am-software.com/bio/matt.html Westford, MA Disclaimer: I disavow all knowledge of this message
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