understanding ipv6 slide: 1 lesson 4 the ipv6 header
TRANSCRIPT
Understanding IPv6 Slide: 1
Lesson 4
The IPv6 Header
Understanding IPv6 Slide: 2
Lesson Objectives
Structure of an IPv6 packet IPv4 header IPv6 header IPv6 extension headers IPv6 MTU Upper layer checksums
Understanding IPv6 Slide: 3
IPv6Header
Upper LayerProtocol Data Unit
Payload
IPv6 Packet
ExtensionHeaders
Structure of an IPv6 Packet
Understanding IPv6 Slide: 4
VersionInternet Header Length
Type of ServiceTotal LengthIdentification
FlagsFragment Offset
Time to LiveProtocol
Header ChecksumSource Address
Destination AddressOptions . . .
Structure of the IPv4 Header
Understanding IPv6 Slide: 5
Version
Traffic Class
Flow Label
Payload Length
Next Header
Hop Limit
Source Address
Destination Address
Structure of the IPv6 Header
Understanding IPv6 Slide: 6
Values of the Next Header Field
Value Header0 Hop-by-Hop Options Header6 TCP17 UDP41 Encapsulated IPv6 Header43 Routing Header44 Fragment Header50 Encapsulating Security Payload51 Authentication Header58 ICMPv659 No next header60 Destination Options Header
Understanding IPv6 Slide: 7
Comparing the IPv4 and IPv6 Headers
IPv4 Header Field Change in IPv6Version New value of 6Internet Header Length RemovedType of Service Traffic Class fieldTotal Length Payload Length fieldIdentification Removed to Fragment headerFragmentation Flags Removed to Fragment headerFragment Offset Removed to Fragment headerTime to Live Hop Limit fieldProtocol Next Header fieldHeader Checksum RemovedSource Address Same, new 128-bit lengthDestination Address Same, new 128-bit lengthOptions Removed (extension headers)
Understanding IPv6 Slide: 8
IPv6 HeaderNext Header = 6 (TCP)
TCP Segment
IPv6 HeaderNext Header = 43 (Routing)
TCP SegmentRouting HeaderNext Header = 6 (TCP)
Authentication HeaderNext Header = 6 (TCP)
IPv6 HeaderNext Header = 43 (Routing)
Routing HeaderNext Header = 51 (AH)
TCP Segment
The Chain of Pointers Formed by the Next Header field
Understanding IPv6 Slide: 9
Extension Headers Order
1. Hop-by-Hop Options header
2. Destination Options header (for intermediate destinations when the Routing header is present)
3. Routing header
4. Fragment header
5. Authentication header
6. Encapsulating Security Payload header
7. Destination Options header (for the final destination)
Understanding IPv6 Slide: 10
Next HeaderHeader Extension Length
Options . . .
Structure of the Hop-by-Hop Options Header
Understanding IPv6 Slide: 11
Option TypeOption Length
Option data . . .
Structure of an Option
Understanding IPv6 Slide: 12
Option Type = 0
Structure of the Pad1 Option
Understanding IPv6 Slide: 13
Option TypeOption Length
Option data . . .
= 1
Structure of the PadN Option
Understanding IPv6 Slide: 14
Option TypeOption Length
Jumbo Payload Length
= 194
= 4
Structure of the Jumbo Payload Option
Understanding IPv6 Slide: 15
Option TypeOption Length
Router Alert Value
= 5
= 2
= 0
Structure of the Router Alert Option
Understanding IPv6 Slide: 16
Next HeaderHeader Extension Length
Options . . .
Structure of the Destination Options Header
Understanding IPv6 Slide: 17
Structure of the Binding Update Option
Option TypeOption Length
FlagsReserved
Prefix LengthSequence Number
LifetimeSub-Options
= 198
. . .
Understanding IPv6 Slide: 18
Structure of the Binding Acknowledgement Option
Option TypeOption Length
StatusSequence Number
LifetimeRefresh
Sub-Options
= 7
. . .
Understanding IPv6 Slide: 19
Option TypeOption Length
Sub-Options
= 8
. . .
Structure of the Binding Request Option
Understanding IPv6 Slide: 20
Option TypeOption Length
Home Address
Sub-Options
= 201
. . .
Structure of the Home Address Option
Understanding IPv6 Slide: 21
Next HeaderHeader Extension Length
Routing TypeSegments Left
Routing type-specific data . . .
Structure of the Routing Header
Understanding IPv6 Slide: 22
Next HeaderHeader Extension Length
Routing TypeSegments Left
ReservedAddress 1
Address N. . .
= 0
Structure of the Routing Type 0 Header
Understanding IPv6 Slide: 23
Next HeaderReserved
Fragment OffsetReserved
More Fragments FlagIdentification
Structure of the Fragment Header
Understanding IPv6 Slide: 24
Unfragmentable part Fragmentable part
Unfragmentable part First fragmentFragment
header
Unfragmentable part Second fragmentFragment
header
Unfragmentable part Third fragmentFragment
header
Original IPv6 Packet
IPv6 Fragmentation Process
Understanding IPv6 Slide: 25
Unfragmentable part Fragmentable part
Unfragmentable part Fragmentable partFragment
header
Unfragmentable part Fragmentable partFragment
header
Unfragmentable partFragmentable
partFragment
header
Original IPv6 Packet
IPv6 Reassembly Process
Understanding IPv6 Slide: 26
Next HeaderPayload Length
ReservedSecurity Parameters Index
Sequence NumberAuthentication Data . . .
Structure of the Authentication Header
Understanding IPv6 Slide: 27
Security Parameters IndexSequence Number
Payload Data
PaddingPadding Length
Next HeaderAuthentication Data
. . .
. . .
. . .
Structure of the ESP Header and Trailer
Understanding IPv6 Slide: 28
IPv6 MTU
Link layer must support a 1280-byte MTU Otherwise, link layer must use a transparent fragmentation and reassembly scheme
For configurable MTU link layers, MTU size of at least 1500 bytes Example: Maximum Receive Unit (MRU) of a Point-to-Point Protocol (PPP) link
Path MTU Discovery process uses the ICMPv6 Packet Too Big message
Understanding IPv6 Slide: 29
Source Address
Destination Address
Upper Layer Packet LengthZero
Next Header
= 0
Structure of the IPv6 Pseudo-Header
Understanding IPv6 Slide: 30
Review
Structure of an IPv6 packet IPv4 header IPv6 header IPv6 extension headers IPv6 MTU Upper layer checksums