[Soekris] Max MTU size

[Jed Clear]

On Sun, 28 Oct 2007, der Mouse wrote:
> > The Via 6105M Chips on the 5501 support 802.1q VLAN tagging, which
> > would be an Ethernet frame size of 1522,
> As I understand it, the maximum standard Ethernet frame is 1516 bytes:
> 6 bytes of destination MAC, 6 of source MAC, 2 of frame type, 1500 of
> payload, and 2 of FCS.  802.1q increases this by 4 (2 for the
> "vlan-tagged" frame type and 2 for the vlan number, basically),
> bringing it to 1520, not 1522.  Where's the mistake?

4 bytes for FCS.

And in the interest of full disclosure, there are a preamble and SFD that
add 8 more bytes berfore the DA.
http://www.javvin.com/protocolEthernet.html

-Jed