$Id: etherstuff.txt,v 1.3 91/05/08 16:15:58 rsbx Exp $

Ethernet specific information for the SANA_II specification:

S2io_DataLength:

	In the case of 802.3 packets, this field is filled with the
	length field from the DTL.

	Otherwise, it is the length of the packet data (same as
	NetBuff.Count for non-raw reads).


Address format:

	Ethernet addresses consist of 47 bits of address information and
	a 1 bit multicast flag. The standard for expressing ethernet
	addresses is as 6 bytes (octets) in the order in which the bytes
	are transmitted with the low-order bits in a byte transmitted
	first. The multicast flag bit is the least-significant bit of the
	first byte.

	Ethernet addresses in a Sana2IOReq occupy the first 6 bytes of
	an address field in transmission order with the low-order bits in
	a byte transmitted first.


Raw reads and writes:

	The data format for a raw read or write is:

		6 bytes of destination address,
		6 bytes of source address,
		2 bytes of type,
		64 to 1500 bytes of data,
		4 bytes CRC value covering all of the above.

	See Ethernet specifications for more information.