It makes no difference when you look at the hardware, but an interesting side-note is that Ethernet is natively little bit-endian. That is, if you're sending a

It makes no difference when you look at the hardware, but an interesting side-note is that Ethernet is natively little bit-endian. That is, if you're sending a byte of data the least significant bit is sent first (think of the pulses of laser light going down a cable). In fact this is true for pretty much all physical layer protocols, as it makes computing the CRC vastly easier. So if you use big-endian byte orders you're actually sending your bits all jumbled up (bits from the most significant byte first, then the least significant bit from within each byte first).