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Date:      Sun, 14 May 1995 10:41:50 +0200 (SAT)
From:      John Hay <jhay@mikom.csir.co.za>
To:        davidg@Root.COM
Cc:        seki@sysrap.cs.fujitsu.co.jp, FreeBSD-Hackers@FreeBSD.org
Subject:   Re: Questions/comments on ed driver
Message-ID:  <199505140841.KAA20547@zibbi.mikom.csir.co.za>
In-Reply-To: <199505121920.MAA00152@corbin.Root.COM> from "David Greenman" at May 12, 95 12:20:49 pm

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> 
> >I examined the ed driver (of 950412 SNAP.)  I found some (essentially
> >2) strangeness in it.  I'm not sure I found bugs or just
> >misunderstood.
> >
> >It is appreciated if you hackers give me comments.
> >
> >1.  If_ed.c defines ETHER_MAX be 1518 and ETHER_MIN 64.  The length
> >includes 4 bytes for CRC.  However, it looks like the program compares
> >them against packet lengths *without* CRC.
> 
>    Actually, the other 4 bytes is for the DS8390 packet header. The comparison
> is correct.
> 
I'm not sure that ETHER_MIN is correct. During December I hacked the NETNS code
to do IPX, so that I could use a FreeBSD box to do IPX routing. I worked fine
with DOS machines and packet drivers. When I used a client with the Novell ODI
drivers it did not work until I changed ETHER_MIN to 60. Now I know that the
ODI driver probably have a bug because they shouldn't care what the size of
the packet is, but that led me to believe that the minimum packet size was too
big. (64 bytes plus 4 for the CRC)

One of my standard patches now is to change ETHER_MIN_LEN to 60.

-- 
John Hay -- jhay@mikom.csir.co.za



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