fxp multicast forwarding problems

Jack Vogel jfvogel at gmail.com
Tue Sep 23 19:06:32 UTC 2008

LOL, sorry to disappoint you but I'm not responsible for fxp, Intel didn't write
it, and i've never touched it :)  Now that wouldnt mean that I can't look at it,
but I am very busy right now, so unless there's no alternative I'd rather not.


On Tue, Sep 23, 2008 at 3:06 AM, Jeremy Chadwick <koitsu at freebsd.org> wrote:
> On Tue, Sep 23, 2008 at 10:46:25AM +0100, Bruce M Simpson wrote:
>> Hi,
>> Whilst doing some QA work on XORP on my desktop, which has fxp0 and
>> msk0, fxp0 got totally hosed.
>> I was running PIM-SM and IGMPv2 router-mode on the box at the time.
>> I wonder if this is related to the problems with fxp multicast
>> transmission I saw back in April.
>> I'm a bit concerned about this as fxp is still a very widespread and
>> useful network chip.
>> I am running 7.0-RELEASE-p4/amd64.
>> sysctls for dev.fxp.0 are set to their default values.
>> I'm not expert on the fxp driver internals, but perhaps someone else has
>> seen this kind of problem before. Multicast-promiscuous mode (aka
>> ALLMULTI) was enabled on the interface. I know some NICs have problems
>> with this, or don't even support it.
>> The errors look like this:
>> fxp0: SCB timeout: 0x10 0x0 0x80 0x0
>> fxp0: SCB timeout: 0x10 0x0 0x80 0x0
>> fxp0: DMA timeout
>> ... repeated ...
>> Attempted workarounds which don't work to un-wedge the chip:
>> Reload the fxp0 microcode with "ifconfig fxp0 link0"
>> Forcibly unloading the kernel module and reloading it
>> Unpatching and repatching at the switch (a cheap 10/100 one)
>> Enabling and disabling promiscuous mode
>> Twiddling dev.fxp.0.noflow
>> The link status looks fine, but the card will not send or receive traffic.
>> A warm reboot was enough to get things back up again.
>> regards,
>> BMS
> Adding Jack Vogel, who's responsible for fxp(4).
> --
> | Jeremy Chadwick                                jdc at parodius.com |
> | Parodius Networking                       http://www.parodius.com/ |
> | UNIX Systems Administrator                  Mountain View, CA, USA |
> | Making life hard for others since 1977.              PGP: 4BD6C0CB |

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