1. Next Generation: Internet Protocol, Version 6 (IPv6) RFC 2460
Geller Bedoya
Joe Contreras
Stephen Ward
Michael Yue

2. RFC 2460
Basic IPv6 header
Initially-defined IPv6 extension headers and options

3. Three reason why IPv6 is needed?

4. Deficiencies of IPv4 IPv4 address exhaustion Internet must accommodate
Real-time audio
Video transmission
No encryption or authentication is provided in IPv4

5. What techniques does IPv4 utilize to fix address exhaustion?

6. Techniques to Reduce Address Shortage in IPv4
Subnetting
Classless Inter Domain Routing (CIDR)
Network Address Translation (NAT)

7. Features of IPv6 Larger Address Space
Aggregation-based address hierarchy
Efficient backbone routing
Efficient and Extensible IP datagram
Stateless Address Autoconfiguration
Security
IPsec mandatory
Mobility

8. Expanded Addressing Capabilities
IPv6 increases the IP address size from 32 bits to 128 bits
~3.4×10^38 addresses
More devices, more addressable nodes
simpler auto-configuration of addresses.
Improvement to/addition of:
Multicasting
Anycasting

9. 128-bit IPv6 Address
3FFE:085B:1F1F:0000:0000:0000:00A9:1234
8 groups of 16-bit hexadecimal numbers separated by “:”
Leading zeros can be removed
3FFE:85B:1F1F::A9:1234
:: = all zeros in one or more group of 16-bit hexadecimal numbers

10. Multicast Addressing
Allow a single device to send a datagram to a group of recipients
Denoted by a preface of 0xFF in the address(1/256 of the address space)
Field is broken into four fields:
Indicator field – 8 Bits
Flags - 4 bits (000X) X=1, Transient
Scope ID – 4 bits
Group ID – 112 bits

11. Anycast Addressing Identifier for a set of interfaces
Packets are routed to the closest interface depending upon distance
Path may change if network configuration changes

12. Header Format Simplification
Since the headers of IPv4 and IPv6 are significantly different
The two protocols are not interoperable
Some IPv4 header fields have been dropped or made optional

13. Simplified Header Format
Description
IPv6: Eight fields spread over 40 bytes
IPv4: at least 12 fields
From 20 until 60 bytes
Improves routing efficiency
Uniformly sized header
Fewer fields to examine and process
ask audience about efficiency.

14. Unchanged Fields

15. Equivalent Fields - address 32 to 128 bits
- total length => payload
- protocol => next header
- TTL => hop limit

16. Removed Fields

17. Major Improvements of IPv6 Header
No option field
Replaced by extension header.
Result in a fixed length, 40-byte IP header
No header checksum
Result in fast processing
No fragmentation at intermediate nodes
Result in fast IP forwarding.

18. Header Comparison Removed (6) Changed (3) IPv4 Added (2) Expanded IPv615 16 31
Removed (6)
vers hlen TOS total length
ID, flags, flag offset
TOS, hlen
header checksum
identification flags flag-offset 20
bytes
TTL protocol header checksum
source address
destination address
Changed (3)
options and padding
total length => payload
protocol => next header
TTL => hop limit
IPv4
vers traffic class flow-label
Added (2)
payload length next header hop limit
traffic class
flow label 40
bytes
source address
Expanded
destination address
address 32 to 128 bits
IPv6

19. IP Header Options
Optional information is placed in separate headers that are placed between the IPv6 header and the next layer header
Makes use of the Next Header field

20. Length of Options
Use of the Next Header field allows for more flexibility with the length of options.

21. Current Extension Headers
Hop-by-Hop Options – Examined at every node along the delivery path
Routing – Lists nodes to visit along the delivery path
Fragment – Facilitates fragmentation for packets larger than a path’s MTU
Destination Options – Contains information that needs to be examined by the destination

22. Advantages More efficient forwarding
Only processed as necessary
Less stringent limits on the length of options
Flexibility for future options
Easier to define new extensions

23. Stateless Address Autoconfiguration (SLAAC)
Motivation
Host self-configuration
Performed using IMCPv6
RFC 4443
3 ways to configure network interfaces:
Stateless
Stateful
Manually

24. Stateless Address Autoconfiguration (SLAAC)
Router
Solicitation
HOST
NEW HOST
HOST
Router
Advertisement
HOST
ROUTER
NEW HOST
ICMPv6 router discovery messages

25. Stateless Address Autoconfiguration (SLAAC)
If Stateless addressing not suitable stateful addressing is used
DHCPv6 (RFC 3315)
Or else manual configuration is performed

26. Flow Labeling Capability
A new capability is added to enable the labeling of packets
Belonging to particular traffic "flows" for which the sender requests special handling
Motivation
Non-default Quality of Service or real-time service

27. Flow Labels Default Flow Label 0 Otherwise
Random value from 0 to 0xFFFFF 3 4 11 12 31
vers traffic class flow-label
payload length next header hop limit
Flow 1 40
bytes
source address
Flow 1:
destination address
IPv6

28. Traffic Class Distinguish different classes and priorities of packets
Provide similar functionality to Type of Service (ToS) from IPv4 3 4 11 12 31
vers traffic class flow-label
payload length next header hop limit
– Low Delay
– High Throughput
– High Reliability 40
bytes
source address
destination address
IPv6

29. Authentication and Privacy Capabilities
Extensions to support
Authentication
Data integrity
Data confidentiality
IPv6 specifications mandate IPsec
Third-generation documents
RFC 4301 & RFC 4309

30. Mobility of IPv6 Large Address Space Automatic Link Configuration
Can support billions of mobile devices
Automatic Link Configuration
Neighbor discovery on home and visited networks
Stateless and Stateful address configuration

32. Questions?