*BSD News Article 33674


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From: ats@first.gmd.de (Andreas Schulz)
Newsgroups: comp.os.386bsd.questions
Subject: Re: Does FreeBSD support two NICs? (3c509)
Message-ID: <5379@bigfoot.first.gmd.de>
Date: 31 Jul 94 23:03:25 GMT
References: <harpCtL4BJ.1FL@netcom.com>
Sender: news@bigfoot.first.gmd.de
Organization: GMD-FIRST
Lines: 32

In article <harpCtL4BJ.1FL@netcom.com>, Greg Harp <harp@netcom.com> wrote:
>I am considering basing a network gateway on FreeBSD, since most of
>the good gateway tools seem to be based on BSD.  In order to do this,
>I need to be able to install two NICs in the machine.  I use 3Com
>3c509's.  
>
>I have read that the drivers may be buggy for the 3c509.  I will
>certainly be paying attention to that.  However, I am still

Should theoretically work, but i fear the driver in FreeBSD 1.1.5.1
is not capable in the moment to drive two cards. 
I hope you won't gate much traffic with it. The problem with the
3com 3C509 cards is, that their FIFO is too small. They only have
a 4Kb send and receive FIFO to store packets. The send side is no
problem, but on the receive side you are getting the problem to
get the bytes fast enough out of the card to the main memory or
to disk(especially the last is the problem). If you are using this
card under NFS with normal sizes, you are getting from every good
workstation 8Kb blasted in from the Network without "gaps". But the
card can only hold the first 4Kb and the rest get lost and need to
be retransmitted and this slows down very much the whole thing.
You can get through that card 400-500Kb send and receive with
a 486, but only if you receiving a file to /dev/null. If you
try to store it to disk you are landing at transfer rates for
receiving wth 30-40Kb.


--
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Andreas Schulz  GMD-FIRST     12489  Berlin-Adlershof  Rudower Chaussee 5
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