Barney Cordoba wrote:
--- On Tue, 8/18/09, Julian Elischer <jul...@elischer.org> wrote:
From: Julian Elischer <jul...@elischer.org>
Subject: Re: [PATCH] Fix for e1000 (em/igb) NOARP issue [Was Re: em(4): sending
ARP regardless of NOARP flag]
To: d...@delphij.net
Cc: pyu...@gmail.com, "Barney Cordoba" <barney_cord...@yahoo.com>, "David Christensen" <davi...@broadcom.com>,
"freebsd-net@freebsd.org" <freebsd-net@freebsd.org>, "Jack Vogel" <jfvo...@gmail.com>, "Jack F Vogel"
<j...@freebsd.org>, yong...@freebsd.org
Date: Tuesday, August 18, 2009, 6:55 PM
Xin LI wrote:
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Barney Cordoba wrote:
--- On Tue, 8/18/09, Pyun YongHyeon <pyu...@gmail.com>
wrote:
From: Pyun YongHyeon <pyu...@gmail.com>
Subject: Re: [PATCH] Fix for e1000 (em/igb)
NOARP issue [Was Re: em(4): sending ARP regardless of NOARP
flag]
To: "Xin LI" <delp...@delphij.net>
Cc: "Barney Cordoba" <barney_cord...@yahoo.com>,
"David Christensen" <davi...@broadcom.com>,
"d...@delphij..net"
<d...@delphij.net>,
"freebsd-net@freebsd.org"
<freebsd-net@freebsd.org>,
"Jack Vogel" <jfvo...@gmail.com>,
"Jack F Vogel" <j...@freebsd.org>,
yong...@freebsd.org,
"Julian Elischer" <jul...@elischer.org>
Date: Tuesday, August 18, 2009, 5:49 PM
On Tue, Aug 18, 2009 at 02:03:37PM
-0700, Xin LI wrote:
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Hash: SHA1
Hi, Jack,
I have looked into the code history and
found that
sys/dev/em/if_em.c,v
1.119 has introduced the arp_ifinit() call
in order to
fix the problem
that if_em won't send ARP when IP address
is changed.
I think we can further improve it as
attached, say,
only do it when
IFF_NOARP is not set. This should
have no effect
for usual
configuration but fix the problem when
NOARP is the
desired behavior.
That change was introduced by me. I guess the
root cause of
the
problem was long initialization time of
hardware which in
turn
resulted in unbearable boot time when
multiple-alias
addresses are
assigned to em(4). I don't remember
details,though.
Since we're in the release cycle, the change
you suggested
would be
quick fix for 8.0. I think em(4)/igb(4) should
remove
SIOCSIFADDR
handling in driver which is layering
violation.
There are 2 kinds of programmers; those who do
things "correctly',
and those that do things that work.
99.99999% of the people will be using ARPs, so
don't be silly and
break the driver to solve a case that almost
no-one cares about please.
Cisco.Ironport runs 50% (2 out of 4) of their em
interfaces in noarp
mode.
Ah, are they running Jack's drivers unmodified? Seems unlikely.
well they will be when they go to 8.
They stay a revision or two back for stability reasons of course.
why wouldn't they?
NOARP does work. Does your network catch on fire if the interface sends
an ARP out? Does equipment start failing like dominos?
well if your network sniffer started responding to arps, how would you
feel?
My point was don't make ARPs not work (the reason the "hack" is in
there is to make something work better) to preserve some fantasy of
"layering" that went out with the 8-track player. The check for
the NOARP flag is a better solution until the subsystem works the
way its supposed to work.
Barney
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