Next Generation IP < IPv6 >

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Next Generation IPlt IPv6 gt
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• National Dong Hwa University
• Director of Computer Center
• Han-Chieh Chao
• ???

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Overview

• Limitations of current Internet Protocol (IP)
• IPv6 addressing
• IPv4/IPv6 Transition
• IPv6 features
• Autoconfiguration
• IPSec
• QoS
• IPv6 Mobility Support
• Summary

3
Internet Growth
4
Internet Growth
5
Growing Pains

• Depletion of IP address
• ( between 2005 and 2001 )
• Explosion of Routing Tables
• ( routing table explosion will condemn the
  internet even sooner than the exhaustion of
  network addresses )

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IPv4 Addresses

• Example 203.64.105.100
• 1100 10110100 00000110 10010110 0100
• (32 bits)
• CB406964
• Maximum 232 4 Billion
• Class A Network 15 Million nodes
• Class B Network 64,000 nodes or less
• Class C Network 250 nodes or less

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IPv4 Address (cont.)

• 127 Class A 16,381 Class B 2,097,151 Class C
  Network 2,113,659 networks total
• Class B is most popular
• 20 of Class B were assigned by 7/90 and doubling
  every 14 months gt Will exhaust by 3/94
• Question Estimate how big will you become?
• Answer more than 256!
• Class C is too small. Class B is just right.

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How many address?

• Some believe 26 to 28 address per host
• Safety margin gt 1015 addresses
• IPng Requirements gt 1012 end systems and 109
  networks. Desirable 1012 to 1015 networks

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Address Size

• H Ratio log10(number of objects)/available bits
• 2n objects with n bits H Ratio log102
  0.30103
• French telephone moved from 8 to 9 digits at 107
  households gt H 0.26 (assuming 3.3 bits/digit)
• US telephone expanded area codes with 108
  subscribers gt H 0.24
• SITA expanded 7-character address at 64k nodes gt
  H 0.14 (assuming 5 bits/char)

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Address Size (cont.)

• Physics/space science net stopped at 15000 nodes
  using 16-bit addresses gt H 0.26
• 3 Million Internet hosts currently using 32-bit
  addresses gt H 0.20 gt A few more years to go

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IPv6 motivation

• The enormous growth of Internet.
• The Address space is running out in IPv4 (32
  bits).
• Routing tables are exploding.
• The lack of security at the network layer
• Device Control Smart Homes
• High Performance Networks
• IP Based Cellular Systems
• Connect everything over IP

• Several years of networking with TCP/IP had
  brought lessons and knowledge
• Lack of Mobility support
• New Applications such as Real Time Multimedia.
• Networked Entertainment - your TV will be an
  Internet host
• More Scalable Solution is needed

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IPv6 Standardization
Where in the standardization process is IPv6?
6ren, vBNS etc. GPRS, UMTS?
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Ipng long term solution

• 1991 Work starts on next generation Internet
  protocols
• -- More than 6 different proposals were
  developed
• 1993 IETF forms IPng Directorate
• --To select the new protocol by
  consensus
• 1995 IPv6 selected
• -- Evolutionary (not revolutionary) step
  from IPv4
• 1996 6Bone started
• 1998 IPv6 standardized
• Today Initial products and deployments

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(No Transcript)
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IPv6 Main Features/Functionality

• expanded addressing and routing capabilities
• support for extension headers and options
• Simplified header format
• quality of service capabilities
• Auto-configuration
• Multi-Homing
• Class of Service/Multimedia support
• support for authentication and privacy
• Multicast (No more broadcast )
• IPv4 , IPv6 Transition Strategy

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IPv4 Header20 OctetsOptions 13 fields,
include 3 flag bits
31
24
0 bits
8
4
16
Ver
IHL
Total Length
Service Type
Identifier
Flags
Fragment Offset
Time to Live
Header Checksum
Protocol
32 bit Source Address
32 bit Destination Address
Options and Padding
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IPv6 Header40 Octets, 8 fields
Version
Class
Flow Label
Payload Length
Next Header
Hop Limit
128 bit Source Address
128 bit Destination Address
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Major Simplifications

• Assign a fixed format to all headers (40 bytes)
• Remove the header checksum
• Remove the hop-by-hop segmentation
• procedure
• Built-in security

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IPv6 Address

• 128 bits long. Fixed size
• 2128 3.41038 addresses gt 6.651023 addresses
  per m2 of earth surface
• If assigned at the rate of 106/?s, it would take
  20 years
• Expected to support 81017 to 21033 addresses
  81017 gt 1,564 address per m2
• Allows multiple interfaces per host
• Allows multiple addresses per interface

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Text Representation of ddresses

• Colon-Hex
• 1080 0 0 0 8 800 200C 417A
• indicates multiple groups of
  16-bits of zeros
• Dot-Decimal
• 203.64.105.100
• Can leave the last 32 bits in dot-decimal,

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Hierachy
35161683280
The remaining 48 bits define the particular
system on the subnetwork.
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IPv6 Address Models

• Allows unicast, multicast, anycast
• Allows provider based, site-local, link-local
• 85 of the space is unassigned
• Addresses have lifetime
• Valid and Preferred lifetime

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Local-Use Address

• Link Local Not forwarded outside the link,
• FE80xxx
• Site Local Not forwarded outside the site,
• FEC0xxx

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Multicast Address

• T0 gt Permanent (well-known) multicast address,
  T1 gt Transient
• Scope 1 Node-local, 2 Link-local, 5 Site-local,
• 8 Organization-local, E Global, F Reserved
• Predefined 1 gt All nodes, 2 gt Routers,
  

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Multicast Address (cont.)

• Link-local scope limits multicast to single
  Ethernet

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Multicast Address (cont.)

• Organization-local scope limits multicast to
  organization boundary

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Anycast Address (the subnet-router address)

• Workstation uses an anycast address to ask for
  help from any router.

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Address Prefixes
Can specify a prefix by /length
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IPv6 Address Allocation
Allocation
Prefix Fraction of
(binary)
Address Space -------------------------------
-------- ------------- Reserved
0000 0000
1/256 (0/8) Unassigned
0000 0001 1/256 (100/8) Reserved
for NSAP Allocation 0000 001 1/128
(200/7) Reserved for IPX Allocation 0000
010 1/128 (400/7) Unassigned
0000 011 1/128
(600/7) Unassigned
0000 1 1/32 (800/5) Unassigned
0001
1/16 (1000/4)
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IPv6 Address Allocation (cont.)
Allocation Prefix
Fraction of
(binary) Address
Space -------------------------------
-------- ------------- Aggregatable
Global Unicast Addresses
001 1/8 (20003) Unassigne
d 1111 0
1/32 (F000/5) Unassigned
1111 10 1/64 (F800/6) Unassigned
1111 110 1/128
(FC00/7) Unassigned
1111 1110 0 1/512 (FE00/9) Link Local
Unicast Addresses 1111 1110 10 1/1024
(FE80/10) Site Local Unicast Addresses
1111 1110 11 1/1024 (FEC0/10) Multicast
Addresses 1111 1111 1/256
(FF00/8)
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IPv6 Extension Headers

• IP options have been moved to a set of optional
  Extension Headers
• Extension Headers are chained together

Next Header
32
Routing Header
Next Header
Routing Type
Num. Address
Next Address
Reserved
Strict/Loose bit mask
Address 1
Address 2
..
Address n
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Routing Header (cont.)

• Strict gt Discard if AddressNext-Address ?
  neighbor
• Type 0 gt Current source routing
• Type gt 0 gt Policy based routing (later)
• New Functionality Provider selection, Host
  mobility, Auto-readdressing (route to new
  address)

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Address Autoconfiguration

• Allow plug and play
• BOOTP and DHCP are used in IPv4
• DHCPng will be used with IPv6
• Two Methods Stateless and Stateful
• Stateless
• A system uses link-local address as source and
  multicasts to "All routers on this link"
• Router replies and provides all the needed prefix
  info
• All prefixes have a associated lifetime
• System can use link-local address permanently if
  no router

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Address Autoconfiguration (cont.)

• Stateful
• Problem w stateless Anyone can connect
• Routers ask the new system to go DHCP server (by
  setting managed configuration bit)
• System multicasts to "All DHCP servers"
• DHCP server assigns an address

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Automatic Renumbering

• Renumbering IPv6 Hosts is easy
• Add a new Prefix to the Router
• Reduce the Lifetime of the old prefix
• As nodes depreciate the old prefix the new Prefix
  will start to be used for new connections
• Renumbering in IPv6 is designed to happen!
• An end of ISP lock in!
• Improved competition

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Transition Mechanism

• Dual Stack Providing complete support for
  both IPv4
• and IPv6 in hosts and routers.

IPv6 host
IPv4 host
Dual IP host
This allows indefinite co-existence of IPv4 and
IPv6, and gradual, app-by-app upgrades to IPv6
usage
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Transition Mechanism (cont.)

• IPv6 over IPv4 tunneling Encapsulating IPv6
  packets within
• IPv4 headers to carry them over IPv4 routing
  infrastructures.

Entry Router
Leaving Router
IPv4 Infrastructure
IPv4 header
Protocol number41
IPv6 packet
IPv6 packet
IPv6 packet
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Transition Mechanism (cont.)

• Encapsulate IPv6 packets inside IPv4 packets(or
  MPLS frames)
• any methods exist for establishing tunnels
• -- configured tunnels - manual
• -- automatic tunnels - IPv4 compatible addresses
  ltipv4gt

• IPv6-to-IPv4 (inter-domain, using IPv4 addr as
  IPv6 site prefix)

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Transition Mechanism (cont.)

• IPv4-compatible IPv6 Addresses

96 bits
32 bits 0000...................
...........00000000 IPv4 address
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Transition Mechanism (cont.)

• IPv4-mapped IPv6 address

80 bits 16 bits 000000
11.11 IPv4
Dest. 1.2.3.4
Dest. FFFF 01020304
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QoS

• Class Field
• Diff Serv Code Point will be used
• Can be used for distinguish between different
  traffic classes
• Flow label
• Identifies streams that needs special handling
• Used by RSVP today
• Not fully defined yet
• Could be used for a deterministic hashkey to
  classify on L2-L7 -gt Would make it easier to
  implement in Hardware

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IPv6 Security

• Two headers in IPv6 that provides security - AH,
  ESP
• AH - Authentication Header
• Provides source authentication
• Integrity
• ESP - Encrypted Security Payload
• Integrity
• Authentication
• Confidentiality
• Note IPSec is exactly the same for IPv4 and IPv6
  only that it was Taylor-made for IPv6.
• Advantages with IPsec
• Network level security
• Transparent to End-user
• Open Standard

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Mobile IPv6

• IPv6 Mobility is based on core features of IPv6
• The base IPv6 was designed to support Mobility
• Mobility is not an Add-on features
• All IPv6 Networks are IPv6-Mobile Ready
• All IPv6 nodes are IPv6-Mobile Ready
• All IPv6 LANs / Subnets are IPv6 Mobile Ready
• IPv6 Neighbor Discovery and Address
  Autoconfiguration allow hosts to operate in any
  location without any special support

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Mobile IPv6 (cont.)

• No Foreign Agent
• In a Mobile IP, an MN registers to a foreign node
  and borrows its address to build an IP tunnel so
  that the HA can deliver the packets to the MN.
  But in Mobile IPv6, the MN can get a new IPv6
  address, which can be only used by the MN and
  thus the FA no longer exists.
• More Scalable Better Performance
• Less traffic through Home Link
• Less redirection / re-routing (Traffic
  Optimisation)

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IPv6 Mobility Support
No FAs, ND, always Co-located Co addresses
for mn.ndhu.tw at
agent.mit.us
mn.ndhu.tw
Router
Home Agent
Correspondend Node
Gets an address trough ND
for mn.ndhu.tw
mit.us
INTERNET
ndhu.tw
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Improved Performance

• Faster processing time per IPv6 packet
• Align on 64 bits boundary
• Fewer Optional Headers (from 12 to 8)
• Removed checksum
• Better designed for HW support
• Scalable hierarchical address architecture
• Faster routing lookups
• Smaller routing tables due to Hierarchical
  address architecture -gt which make ip_forwarding
  faster and more efficient use of the memory
• Less routing traffic in the backbone -gt which
  mean less load on the network

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Summary

• Streamlined Header Format
• Flow Label
• 128-bit Network Addresses
• Elimination of Header Checksum
• Fragmentation only by source Host
• Extension Headers
• Built-in-security