Re: CRC errors with gem(4)

[Darren Reed <darrenr%netbsd.org@localhost>]

Julian Coleman wrote:
> Hi,
> 
> I should have pointed out that the "ethertype Unknown" packets always start:
> 
>   20f7 8e80 0003 wwxx yyzz 0800 ba68 354a
>   0800 4500
> 
> instead of:
> 
>   0800 20f7 8e80 0003 ba68 354a 0800 4500
> 
> The destination MAC address (0800 20f7 8e80) is in bytes 10, 11, 0, 1, 2, 3.
> 
> The source MAC address is (0003 ba68 354a) in bytes 4, 5, 12, 13, 14, 15
> 
> Bytes 6-9 appear to be either parts of the data (3738 393a in this case)
> or sometimes 0000 0000.
> 
> The IP and TCP parts of the mangled packets are sometimes intact, sometimes
> part zeros.

If I understand you correctly, the implication here is that the
bytes are being transmitted corrupt.

At what packet rate (pps) do you start to see problems?
Is hardware checksum enabled?
If so, does disabling it improve matters?
Are there any comments/workarounds in opensolaris code
for a problem that resembles this?

Darren