fxp multicast forwarding problems

Jeremy Chadwick koitsu at FreeBSD.org
Tue Sep 23 10:06:04 UTC 2008

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,

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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