Payload for IP over Ethernet : IPv6 over IPv4

[Steve Deering]

At 2:03 PM +0900 4/24/00, Ettikan Kandasamy wrote:
>MTU for Ethernet is 1514 bytes and 14 bytes is for ethernet header leaves
>1500 bytes for payload.

A technical nit:  As used by the IP community, the MTU of a link refers
to the maximum IP packet size that can be transmitted on the link without
doing fragmentation.  Thus, the MTU of Ethernet is 1500 bytes, not 1514.

>So it looks as follows for TCP for IPv4 , IPv6 , IPv6 over v4 and IPv4 over v6
>
>                     v4        v6        v6 over v4     v4 over v6
>
>IP Header           20        40                    20       40
>IP Payload               1480       1460                       1480
>1460
>         Header
>(for v6 )            40   (for v4)          20
>         Payload
>1440                      1440
>TCP header                    20              20                  20        20
>TCP payload                    1460      1440                       1420
>1420
>Any options ...            xxx     xxx                       xxx
>xxx
>(Actual payload)      yyy       yyy                                        yyy
>yyy
>
>
>Am I right !!!

Because of inconsistent spacing and random line-breaking, the columns in
your table don't line up and I cannot understand it.  Please send again,
but when you type it in, use a fixed-width font, no tab characters, and
a carriage return at the end of each line in the table.

Steve