Re: Trap 0x34 panic on 5.1 on Blade 100

[Julian Coleman <jdc%coris.org.uk@localhost>]

Hi,

> After further testing, it appears that I only get panics when using the
> on-board gem interface with a 100Mb half-duplex connection.
> Specifically, when connected to a 3Com SuperStack II Dual Speed Hub 500.

> I haven't configured any packet filters but I am using dhclient and
> dhclient uses bpf. As a test, I disabled dhclient, set a static IP
> address, and found that the panics stop. Instead I see network
> errors like this:
> 
> gem0: discarding oversize frame (len=6330)
> gem0: receive error: CRC error
> gem0: discarding oversize frame (len=6330)
> gem0: discarding oversize frame (len=6330)
> gem0: receive error: CRC error
> 
> The oversize frame messages may be bogus, the hub has an RMON agent and
> that reports collisions and fragments but no oversize packets.

I wonder what causes the gem interface to garble packets.  Does `ifconfig
gem0` report full-duplex for the link?  A duplex mismatch could cause
problems.  However, I'm still not sure what data causes the kernel to crash
later.

Thanks,

J

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