1. The Next Generation Protocol
IPv6 :
The Next Generation Protocol
Surasak Sanguanpong
Last updated: May 24, 1999

2. Agenda IPv4’s limitations Protocol Features Addressing
IPv4 V.S. IPv6 functional comparison
IPv4 to IPv6 migration
Conclusion

3. IPv4’s limitations addressing : address depletion concerns
Two driving factors : addressing and routing
addressing : address depletion concerns
IPv4 address space would exhaust between 2005 and 2011 [RFC1752]
routing : routing table explosion
currently ~50K entries in core routers
more factors...
opportunity to optimized on many years of deployment experience
new features needed : multimedia, security, mobile, etc..
At some point in the near future the Internet will require a deployed new version of the Internet protocol. Two factors are driving this: routing and addressing. Global internet routing based on the on 32-bit addresses of IPv4 is becoming increasingly strained. IPv4 address do not provide enough flexibility to construct efficient hierarchies which can be aggregated. The deployment of Classless Inter- Domain Routing is extending the life time of IPv4 routing by a number of years, the effort to manage the routing will continue to increase. Even if the IPv4 routing can be scaled to support a full IPv4 Internet, the Internet will eventually run out of network numbers. There is no question that an IPng is needed, but only a question of when.

4. Key Issues support large global ๐ internetworks ๐ have a clear way to
The new protocol MUST : ๐
support large global
internetworks
IPv4
IPv4
IPv4
IPv4
IPv4
IPv4
IPv4
IPv4
IPv4
IPv4
IPv4
IPv4
IPv4
IPv4
IPv4
IPv4
IPv4
IPv4
IPv4
IPv4 ๐
have a clear way to
transition IPv4 based networks
IPv4
There are several key issues that should be considered when reviewing the design of the next generation internet protocol. Some are very straightforward. For example the new protocol must be able to support large global internetworks. Others are less obvious. There must be a clear way to transition the current large installed base of IPv4 systems. It doesn't matter how good a new protocol is if there isn't a practical way to transition the current operational systems running IPv4 to the new protocol.

5. History of the IPv6 Effort (1)
1990 : IETF defined a new version of IP, generally later called IP Next Generation or IPng
Spring 1992 :
IAB proposed the OSI CLNP (Connectionless Network Protocol).
Finally rejected by IETF and working groups

6. History of the IPv6 Effort (2)
Feb 1992: 4 proposals for IPng
CNAT, IP Encaps, Nimrod, Simple CLNP
March 1992: evolving
IP Encaps to IPAE (IP Address Encapsulation)
Simple CLNP to TUBA (TCP and UDP with bigger Address)
Dec 1992: 3 more proposals for IPng
PIP (P Internet Protocol), SIP (Simple IP), and TP/IX
Fall 1993 : resolution to 3 possibilities :
TUBA
TP/IX => CATNIP (Common Architecture for the Next Generation Internet Protocol)
SIP+IPAE+PIP=> SIPP (Simple Internet Protocol Plus)
Jul 1994 : SIPP was chosen, known as IPv6

7. IPv6 key advantages 128 bits fixed length IP address real time support
self-configuration of workstations
security features
support mobile workstations
protocol remains the same principle
IPv4 compatibility

8. IPV6 address representation
Hexadecimal values of the eight 16-bit pieces
x:x:x:x:x:x:x:x
Example
FEDC:BA98:7654:3210:FEDC:BA98:7654:3210
1080:0:0:0:8:800:200C:417A
Compressed form: "::" indicates multiple groups of 16-bits of zeros.
1080:0:0:0:8:800:200C:417A ::8:800:200C:417A
FF01:0:0:0:0:0:0: FF01::101
0:0:0:0:0:0:0: ::1
0:0:0:0:0:0:0: :: ๐

9. IPV6 address representation, cont
mixed environment of IPv4 and IPv6 address
IPv4-compatible IPv6 address
technique for hosts and routers to dynamically tunnel IPv6
packets over IPv4 routing infrastructure
0:0:0:0:0:0: => ::
IPv4-mapped IPv6 address
represent the addresses of IPv4-only nodes (those that
do not support IPv6) as IPv6 addresses
0:0:0:0:0:FFFF: => ::FFFF:

10. Format Prefix IPv6-address/prefix-length
leading bits indicate specific type of an IPv6 address
variable-length field represented by the notation:
IPv6-address/prefix-length
Example : the 60-bit prefix 12AB CD3
12AB:0000:0000:CD30:0000:0000:0000:0000/60
12AB::CD30:0:0:0:0/60
12AB:0:0:CD30::/60

11. Type of addresses Unicast: defines a single interface.
Three type of addresses
Unicast:
defines a single interface.
A packet sent to a unicast address is delivered to the interface
identified by that address.
Anycast:
defines a set of interfaces
A packet sent to an anycast address is delivered
to one of the interfaces
Multicast:
defines a set of interfaces
A packet sent to a multicast address is delivered to
all interfaces identified by that address

12. IPV6 address allocation

13. Aggregatable Unicast Address
Three level hierarchy:
Public Topology : providers and exchanges who provide public Internet transit services
(P1, P2, P3, P4, X1, X2, P5 and P6)
Site Topology : does not provide public transit service to nodes outside of the site
(S1, S2, S3, S4, S5 and S6)
Interface Identifier: interfaces on links X1 P1 P2 P3 P4 x2 P5 P6 S1 S2 S3 S4 S5 S6
FP TLA ID RES NLA ID SLA ID Interface ID
bits
Public Topology
Site
Topology
Interface
Identifier
TLA = Top Level Aggregation
RES = Reserved
NLA = Next-Level Aggregation
SLA = Site-Level Aggregation
FP=Format
Prefix= 001

14. Header comparison Removed (6) Changed: (3) Added: (2) Expanded IPv4
ID, Flags, frag offset
TOS, hlen
header checksum
Changed: (3)
total length=> payload
protocol => next header
TTL=> hop limit
Added: (2)
traffic class
flow label
Expanded
address 32 bits to 128 bits
vers hlen TOS total length
identification flags frag offset
TTL protocol header checksum
source address
destination address
options and padding 20
bytes
IPv4
vers traffic class flow label
pay load length next header hop limit
source address
destination address 40
bytes
IPv6

15. Autoconfiguration “Plug and play” feature Stateless mode :
via ICMP (no server required)
Prefix
4c00::/80
Link Address
00:A0:C9:1E:A5:B6
IPv6 Address
4c00::00:A0:C9:1E:A5:B6 + =
Router adv.
Stateful server mode :
via DHCP
DHCP request
00:A0:C9:1E:A5:B6
DHCP
server
DHCP response
4c00::00:A0:C9:1E:A5:B6

16. Multimedia support Flow1 Flow2
Applications reserve resources in advance via Flow Label
Workstation
Flow1
File Server PC
Multimedia
Server
Flow2
All packets belonging to the same flow must be sent with
the same source/destination address, traffic class, and flow label

17. Security Authentication/Confidential Authentication: MD5 based
payload encryption
Cipher Block Chaining mode of the Data Encryption Standard (DES-CBC)

18. Support Protocols ICMPv6 [RFC1885] DHCPv6
DNS extensions to support IPv6 [RFC1886]
Routing Protocols
RIPv6 [RFC2080]
OSPFv6
IDRP
IS-IS
Cisco EIGRP

19. Transition Strategy Dual Stack run both IPv4 and IPv6 Tunneling
IPv6 packet over IPv4 infrastructure
Header Translation
IPv4-only by header translation

20. Dual Stack Dual stack hosts support both IPv4 and IPv6
Determine stack via DNS
Application
TCP
IPv6 IPv4
Ethernet
IPV6
Dual stack host
IPv4

21. Tunneling: automatic tunneling
Encapsulate IPv6 packet in IPv4
rely on IPv4-compatible IPv6 address
IPv6 host
IPv4
Network
IPv4/6 host :: R1 R2 ::
6 traffic flow label
payload len next hops
src = ::
(IPv4-compatible IPv6 adr)
dst = ::
payload
4 hl TOS len
frag id frag ofs
TTL prot checksum
src:
dst:
6 traffic flow label
payload len next hops
src = ::
(IPv4-compatible IPv6 adr)
dst = ::
payload
4 hl TOS len
frag id frag ofs
TTL prot checksum
src:
dst:
6 traffic flow label
payload len next hops
src = ::
(IPv4-compatible IPv6 adr)
dest = ::
payload

22. Tunneling : configured tunneling
IPv6 host
IPv6 host
IPv4
Network
2000::A:A:B:C:D
2000::B:B:C:D:E
IPv6 address
(IPv4-compatible
address are
unavailable) R1 R2
::2000:B:B:C:D:E R2
::2000:B:B:C:D:E
6 traffic flow label
payload len next hops
src = 2000:A:A:B:C:D
(IPv6 adr)
dst = 2000:B:B:C:D:E
(IPv6 adr)
payload
4 hl TOS len
frag id frag ofs
TTL prot checksum
src = R1
dst =R2
6 traffic flow label
payload len next hops
src = 2000:A:A:B:C:D
(IPv6 adr)
dst = 2000:B:B:C:D:E
(IPv6 adr)
payload
6 traffic flow label
payload len next hops
src = 2000:A:A:B:C:D
(IPv6 adr)
dst = 2000:B:B:C:D:E
(IPv6 adr)
payload
Encapsulate IPv6 packet in IPv4
rely on IPv6-only address

23. Header Translation Full IPv6 system
need to support fewIPv4-only systems
rely on IPv4-mapped IPv6 address
IPv6 host
IPv4 host
IPv6
Network
::FFFF: R1 R2
::FFFF:
::FFFF:
6 traffic flow label
payload len next hops
src = ::FFFF:
(IPv4-mapped IPv6 adr)
dst = ::FFFF:
payload
6 traffic flow label
payload len next hops
src = ::FFFF:
(IPv4-mapped IPv6 adr)
dst = ::FFFF:
payload
4 hl TOS len
frag id frag ofs
TTL prot checksum
src =
dst =
payload

24. Migration Steps (1) upgrade DNS servers to handle IPv6 Address
(2) Introduce dual stack systems that support IPv4
and IPv6
(3) Rely on tunnels to connect IPv6 networks separated by IPv4 networks
(4) remove support for IPv4
(5) rely on header translation for
IPv4-only systems

25. Conclusion
IPv6 will provide for future Internet growth and enhancement
IPv6 :
solve the Internet scaling problem
support large hierarchical address
provide a flexible transition mechanism
interoperate with IPv4
provide a platform for new Internet functionality

26. More Information Books WWW
IPng: Internet Protocol next Generation, S. Bradner and A. Mankin, Addison-Wesley, 1996.
IPng and the TCP/IP Protocols, Stephen A. Thomas, John Wiley & Sons, 1996.
IPv6 : The New Internet Protocol, Christian Huitema, Prentice Hall,1996.
WWW