Date: Sun, 1 Sep 2002 23:08:29 -0700 From: Luigi Rizzo <rizzo@icir.org> To: Jui-Nan Eric Lin <ericlin@ericlin.cabin.idv.tw> Cc: freebsd-net@FreeBSD.ORG Subject: Re: Question about bridge(4): loop without physical loop Message-ID: <20020901230828.A83423@iguana.icir.org> In-Reply-To: <002b01c25217$a6842a00$fa01a8c0@synvision.com.tw>; from ericlin@ericlin.cabin.idv.tw on Mon, Sep 02, 2002 at 08:28:24AM %2B0800 References: <001101c24f3f$e39f5840$fa01a8c0@synvision.com.tw> <20020830090012.A53982@iguana.icir.org> <002b01c25217$a6842a00$fa01a8c0@synvision.com.tw>
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On Mon, Sep 02, 2002 at 08:28:24AM +0800, Jui-Nan Eric Lin wrote:
> hi,
>
> I have searched with keyword "aa:aa:aa:aa:aa:aa" and get the same result.
> It said that those might be collisions on the net. So I tried to reduce
> collisions, but the message still appears. (not frequently)
> If you have made a patch, please let me know. Thanks.
one thing to try could be in sys/net/if_ethersubr.c:ether_input()
before the call to bridge_in_ptr() add
if (m->m_len < 42) { /* XXX */
m_freem(m);
return;
}
A min-sized frame is 60 bytes + CRC, but in that point you have
already subtracted the MAC header and the CRC so the comparison
should be against 46. However, if this pkt is a VLAN one, you
might conceivably have shaved another 4 bytes so make it 42.
If (in a future) we are going for multiple encapsulations the
threshold could become even lower, but this is not the case now.
cheers
luigi
> Sincerely,
> Jui-Nan Eric Lin
>
> ----- Original Message -----
> From: "Luigi Rizzo" <rizzo@icir.org>
> To: "Jui-Nan Eric Lin" <ericlin@ericlin.cabin.idv.tw>
> Cc: <freebsd-net@FreeBSD.ORG>
> Sent: Saturday, August 31, 2002 12:00 AM
> Subject: Re: Question about bridge(4): loop without physical loop
>
>
> > hi,
> > these might be runt packets deriving e.g. from junk on the link.
> > It is the first time that i see such reports so haven't
> > worried too much about it.
> > a possible fix could be to avoid bridging of packets that are
> > too short for the ethernet specs or have crc errors.
> >
> > if the problem shows up frequently and you are willing to try some
> > patches let me know, i could try to send you some code to
> > fix this.
> >
> > cheers
> > luigi
> >
> > On Thu, Aug 29, 2002 at 05:38:19PM +0800, Jui-Nan Eric Lin wrote:
> > > Hi, all:
> > >
> > > I have installed bridge on my freebsd box, but the message showed on the
> > > screen frequently and the network halted (packet missing):
> > >
> > > /kernel: -- loop (0) 55.55.55.55.55.55 to fxp1 from fxp0 (active)
> > > /kernel: -- loop (0) 55.55.55.55.55.55 to fxp0 from fxp1 (active)
> > >
> > > It' weird because I didn't have a NIC which has mac address
> > > 55.55.55.55.55.55.
> > > I have searched with Google, and found the message below:
> > >
> > >
> http://docs.freebsd.org/cgi/getmsg.cgi?fetch=180949+0+archive/2002/freebsd-n
> > > et/20020707.freebsd-net
> > >
> > > It seems that bridge supports only NICs with "SIMPLEX" flag.
> > > Therefore, I checked result of "ifconfig -a", but my two Intel 82550
> (fxp0,
> > > fxp1) has "SIMPLEX" flag:
> > >
> > > fxp0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu
> 1500
> > > fxp1: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu
> 1500
> > >
> > > Any suggestion?
> > >
> > > P.S. #1 sysctl -a | grep bridge
> > >
> > > #sysctl -a | grep bridge
> > > net.link.ether.bridge_cfg: fxp0,fxp1
> > > net.link.ether.bridge: 1
> > > net.link.ether.bridge_ipfw: 1
> > > net.link.ether.bridge_ipf: 0
> > > net.link.ether.bridge_ipfw_drop: 0
> > > net.link.ether.bridge_ipfw_collisions: 749
> > >
> > > P.S.#2 Sorry for my poor English :)
> > >
> > > Sincerely,
> > > Jui-Nan Eric Lin
> > >
> > >
> > > To Unsubscribe: send mail to majordomo@FreeBSD.org
> > > with "unsubscribe freebsd-net" in the body of the message
> >
>
>
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