| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Destination Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Version 4-bit Internet Protocol version number = 6.
Traffic Class 8-bit traffic class field. See section 7.
Flow Label 20-bit flow label. See section 6.
Payload Length 16-bit unsigned integer. Length of the IPv6
payload, i.e., the rest of the packet following
this IPv6 header, in octets. (Note that any
RFC 2460 IPv6 Specification December 1998
extension headers [section 4] present are
considered part of the payload, i.e., included
in the length count.)
Next Header 8-bit selector. Identifies the type of header
immediately following the IPv6 header. Uses the
same values as the IPv4 Protocol field [RFC-1700
et seq.].
Hop Limit 8-bit unsigned integer. Decremented by 1 by
each node that forwards the packet. The packet
is discarded if Hop Limit is decremented to
zero.
Source Address 128-bit address of the originator of the packet.
See [ADDRARCH].
Destination Address 128-bit address of the intended recipient of the
packet (possibly not the ultimate recipient, if
a Routing header is present). See [ADDRARCH]
and section 4.4.
RFC 2460 IPv6 Specification December 1998
4. IPv6 Extension Headers
In IPv6, optional internet-layer information is encoded in separate
headers that may be placed between the IPv6 header and the upper-
layer header in a packet. There are a small number of such extension
headers, each identified by a distinct Next Header value. As
illustrated in these examples, an IPv6 packet may carry zero, one, or
more extension headers, each identified by the Next Header field of
the preceding header:
+---------------+------------------------
| IPv6 header | TCP header + data
| |
| Next Header = |
=3= |