Quentin Garnier <netbsd@quatriemek.com> writes:

> Unless I'm deeply mistaken, since I've been through the documentation of
> the DP83815 recently, the 802.1Q overhead is 4 bytes, which make frames of
> 1518 bytes for 1500 bytes of data.
> 
> What am I not getting? The CRC?

1518 + 4 bytes of FCS, which is passed to the host with these
chips. The datasheet seems to specify frame sizes with FCS most of the
time.

Quoth the datasheet, "When ALP is set to 0, packets larger than 1518
bytes (CRC inclusive) will be truncated at 1514 bytes, and rejected if
possible." A tagged frame of 1522 bytes (incl. FCS) will then get
truncated.

 -v