FreeBSD boots too fast on Dell PE850

[Martin Horcicka]

2006/8/18, Pyun YongHyeon <pyunyh at gmail.com>:
> On Fri, Aug 18, 2006 at 10:51:07AM +0200, Martin Horcicka wrote:
>  > 2006/8/18, Dan Nelson <dnelson at allantgroup.com>:
>  > >In the last episode (Aug 17), Alan Amesbury said:
>  > >> OK, booting *too* quickly is a somewhat unusual problem.....  I have
>  > >> FreeBSD 6.1-RELEASE-p3 running on a Dell PowerEdge 850.  For some
>  > >> reason, in the PowerEdge 850 Dell chose to replace the perfectly
>  > >> adequate em(4) adapters found on the PE750 with bge(4) hardware.
>  > >> FreeBSD identifies these adapters as BCM5750A1, but Dell says they're
>  > >> actually Broadcom 5721J adapters instead.  See
>  > >>
>  > >> http://www.dell.com/downloads/global/products/pedge/en/850_specs.pdf
>  > >>
>  > >> for details.  The switch to which the host is connected is a Cisco
>  > >> Catalyst 3750.  How this relates to FreeBSD, however.....
>  > >
>  > >Have you enabled portfast on the Cisco?
>  > >
>  > >http://www.cisco.com/warp/public/473/12.html#c2k
>  >
>  > We have similar problems on various hardware and we also believe it's
>  > caused by the Spanning Tree Protocol procedure done during the switch
>  > port initialization. I don't like the idea of using portfast as it
>  > makes the switch less robust so I tried to delay the boot using an rc
>  > script as well:
...
> I think it's job of device driver. If the driver find its link
> negotiation is in progress it should not send frames.
> Unfortunately not all drivers handle this correctly.

Unfortunately, I don't know how it works exactly. In our case when the
autodetection is disabled and there is e.g. 100/full configured
manually on both, switch and the FreeBSD box, ifconfig shows the
interface status wery early as "active". I suspect the switch (Cisco)
to activate the port (from the point of view of the FreeBSD box) but
not to forward any "normal" frames until the Spanning Tree Protocol
procedure is finished for that port. But it's just a guess. I don't
know the negotiation protocol in Ethernet at all and I would really
welcome a commentary from someone who does.

Martin