IPv6 Fragment Header.
RFC2460
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Next Header | Reserved | Fragment Offset |Res|M|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identification |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Next Header 8-bit selector. Identifies the initial header
type of the Fragmentable Part of the original
packet (defined below). Uses the same values as
the IPv4 Protocol field [RFC-1700 et seq.].
Reserved 8-bit reserved field. Initialized to zero for
transmission; ignored on reception.
Fragment Offset 13-bit unsigned integer. The offset, in 8-octet
units, of the data following this header,
relative to the start of the Fragmentable Part
of the original packet.
Res 2-bit reserved field. Initialized to zero for
transmission; ignored on reception.
M flag 1 = more fragments; 0 = last fragment.
Identification 32 bits. See description below.