Transcript goh_siew_lim_dc3

IPv6
INTRODUCTION
INTRODUCTION
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Internet Protocol version 6 (IPv6)
=Internetworking Protocol next generation (IPng)
enabling a wider range of Internet-connected
devices
to replace IPv4
designed by IETF
(Internet Engineering Task Force )
recommended by IPng Area Directors of IETF at
Toronto IETF meeting on 25 July 1994.
INTRO (Cont…)
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IPv6 was adopted because:
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The use of address space is inefficient.
The Internet must accommodate real-time
audio and video transmission.
IPv4 provided no security mechanism.
IPv6 offers automatic addressing.
INTRO (Cont…)
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3 types of address:
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Additional fields included in IPv6 header
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Unicast addressing
Multicast addressing
Anycast addressing
priority field, flow field.
IPv6 is a natural increment to IPv4.
IPv6
NEW CHANGES IN IPv6
New changes in IPv6
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simplified header format
The IPv6 header format is simpler than IPv4
longer address fields
The length of address field is extended the bits. The
address structure also provides more levers of hierarchy.
Flexible support for opinion
The length of address field is extended the bits. The
address structure also provides more levers of hierarchy.
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Flow label capability
The options in appear in optional extension headers that
are encoded in more efficient and flexible fashion than
they were in IPv4.
Security
IPv6 supports built-in authentication and confidentiality.
Large packets
IPv6 supports built-in authentication and confidentiality.
Fragmentation at source only
IPv6 supports payloads that are longer than 64 kilo bytes,
call jumbo payloads.
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No checksum field
The checksum field has been removed to reduce
packet processing time in a router. Packets carried
by the physical network such as Ethernet, ATM
are typically already checked.
IPv6
TRANSITION FROM
IPv4 TO IPv6
Transition from IPv4 to IPv6
Dual-Stack
- Strategies, which allow IPv4 and IPv6 to communicate in
the same devices and networks.
 Tunneling
- Techniques, to avoid order dependencies when upgrading
hosts, routers or regions.
 Translation
- Techniques, to allow IPv6 only devices to communicate
with IPv4-only devices.
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IPv6
IPv6 HEADER
Introduction
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more simpler
efficient
reduce process cost
Base Header
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Version
- Specifies the version number
- 4 bits
Priority
- Priority of the packet with respect to traffic congestion
- Congestion-controlled (0-7)
- Noncongestion-controlled (8-15)
- 4 bits
Traffic Class
- Class of service desired for the datagram
- 8 bits
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Flow Label
- Provide special handling for a particular flow of data
- 20 bits
Payload Length
- Length of the data field (excluding the base header) in the
datagram
- 16 bits
Next Header
- Defining the header that follows the base header in datagram
- 8 bits
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Hop Limit
- Specifies the maximum number of hops a packet
may travel before reaching the destination
- 8 bits
Source Address
- Identifies the original source of the datagram
- 128 bits
Destination Address
- Identifies the final destination of the datagram
- 128 bits
IPv6
IPv6 EXTENSION HEADER
IPv6 EXTENSION HEADER
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Extension headers
support extra functionalities.
placed between the basic header and the
payload.
each of them contains its own Next Header
Field. (daisy chained )
are placed in order.
DAISY-CHAIN EXTENSION HEADER
Basic header
Next header=
TCP
TCP segment
Basic header Routing header Fragment
Authentication
Next header=Next header= header
Header
TCP
routing
fragment
Next header= Next header= segment
authentication TCP
TYPES OF EXTENSION HEADERS
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Hop-by-hop options header (header code:0)
Routing header (header code:43)
Fragment header (header code:44)
Authentication header (header code: 51)
Encapsulating security payload header
(header code:52)
Destination options header (header code:60)
HOP-BY-HOP OPTIONS HEADER
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Implement an efficient method to alert routers
of a packet that requires special processing.
ROUTING HEADER
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used by the source to control the routing of
packet.
explicitly dictate the route from the source to
the destination.
contains a list of one or more intermediate
nodes to be visited on the way to a packet’s
destination.
FRAGMENT HEADER
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allows fragmented packets to traverse the
IPv6 network.
Performing by source nodes, not by routers
along a packet’s delivery path.
simplifies the routers’ work and makes
routing go faster.
will discards the packet that is too big
send an ICMP packet back to the source
use a path MTU discovery technique to find the
smallest MTU supported by any network on the path
Source then fragments by using this knowledge
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Otherwise, the source must limit all packets
to 1280 octets(the minimum MTU that must
be supported by each network).
AUTHENTICATION HEADER
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uses an algorithm to ensure that the IPv6 packet has
not been altered along its path.
Ensures that the IPv6 packet has arrived from the
sourced listed in the IP Header.
Provides a mechanism by which the receiver of a
packet can be sure of who sent it.
Use cryptographic techniques to encrypt the
contents of a packet so that only the intendend
recipient can read it.
ENCAPSULATING SECURITY
PAYLOAD HEADER
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For packets that must be sent secretly.
Provide confidentiality and privacy.
DESTINATION OPTION HEADER
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optional information to be examined by the
destination node.
Not use during routing.
IPv6
IPv6 ADDRESSING
Brief Introduction
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Provides 128 bit address space
allows for 2128 ≈ 1040 different addresses
can address 3.4 x 1038 nodes if address
assignment efficiency is 100%.
3 basic types:
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Unicast
Anycast
Multicast
Unicast Address
 Corresponds
to a single computer
 The format is:
010
Registry
Provider
Subscriber
Subnet
Interface
Unicast Address
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3 types of Unicast Address
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Global unicast
n bits
m bits
128 – n – m – bits
Global Routing Prefix
Subnet Id
Interface ID
Site-local unicast
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it is designed to used for addressing inside of a site
without the need for a glocal prefix
10 bits
54 bits
64 bits
1111111011
Subnet ID
Interface ID
Unicast Address
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Link - local unicast
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it is used on a single link. The addresses are designed
on a single link for purposes such as automatic address
configuration, neighbor discovery, or when no routers
are present
10 bits
54 bits
64 bits
1111111010
0
Interface ID
Anycast Address
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assigned to more than one interface, with the
property that a packet sent to an anycast
address is routed to the “nearest” interface
having that address, according to the routing
protocols’ measurement.
allocated from the unicast address space by
using any of the defined unicast address
formats
Anycast Address
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A longest prefix P identifies the topological region in
which all interfaces belonging to that anycast
address reside.
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Within the region identified by P, the anycast address
must be maintained as a separate entry in the
routing system
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Outside the region identified by P, the anycast
address may be aggregated into the routing entry for
prefix P.
Multicast Address
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Pre-defined Multicast addresses
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defined for explicit scope values
The following slide shows the reserved
Multicast Addresses. This reserved
addresses shall never be assigned to any
multicast group.
Multicast Address
FF00:0:0:0:0:0:0:0
FF01:0:0:0:0:0:0:0
FF02:0:0:0:0:0:0:0
FF03:0:0:0:0:0:0:0
FF04:0:0:0:0:0:0:0
FF05:0:0:0:0:0:0:0
FF06:0:0:0:0:0:0:0
FF07:0:0:0:0:0:0:0
FF08:0:0:0:0:0:0:0
FF09:0:0:0:0:0:0:0
FF0A:0:0:0:0:0:0:0
FF0B:0:0:0:0:0:0:0
FF0C:0:0:0:0:0:0:0
FF0D:0:0:0:0:0:0:0
FF0E:0:0:0:0:0:0:0
FF0F:0:0:0:0:0:0:0
Multicast Address
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All nodes addresses
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identify the group of all IPv6 nodes within 1 scope
1 (interface-local) or 2 (link-local).
FF01:0:0:0:0:0:0:1
FF02:0:0:0:0:0:0:1
Multicast Address
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All routers addresses
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identify the group of all IPv6 routers within scope
1 (interface-local), 2 (link-local), or 5 (site-local).
FF01:0:0:0:0:0:0:2
FF02:0:0:0:0:0:0:2
FF05:0:0:0:0:0:0:2
Multicast Address
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Solicited-Nodes Address:
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Computed as a function of a node’s unicast and anycast
addresses
formed by taking the low-order 24 bits of an address
(unicast or anycast) and appending those bits to the prefix
FF02:0:0:0:0:1:FF00::/104 resulting in a multicast address
in the range FF02:0:0:0:0:1:FF00:0000 to
FF02:0:0:0:0:1:FFFF:FFFF.
Format:
FF02:0:0:0:0:1:FFXX:XXXX
Address Notation
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Normally, a 128-bit number written in dotted
decimal notation:
105.220.136.100.255.255.255.255.0.0.18.128.140.10.255.255
Address Notation
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Colon Hexadecimal Notation
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Reduced the number of characters used to write
an address
each group of 16 bits is written in hexadecimal
with a colon separating groups
105.220.136.100.255.255.255.255.0.0.18.128.140.10.255.25
69DC:8864: FFFF: FFFF: 0:1280:8C0A: FFFF
Address Notation
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Zero Compression
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replaces sequences of zeros with double
semicolons
can only once per address
Example:
FDEC: 0:0:0:0: BBFF: 0: FFFF
can be written as
FDEC:: BBFF:0:FFFF
Address Notation
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If the 0 string begins the address, the
notation starts with the double colon.
Example:
0000:0000:0000:0000:0AFF:1BDF:000F:0077
can be written as
:: 0AFF:1BDF:F:0077
Address Notation
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CIDR Notation.
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The example below show how can we define a
prefix of 60 bits using CIDR.
FDEC: 0:0:0:0: BBFF: 0: FFFF/60
IPv6
CONCLUSION
CONCLUSION
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IPv6 come at the right time- Internet growing
so rapidly.
Solution of the new disruptive applications.
IPv4 IPv6 -larger task for some company or
industry, but the rate of IPv4 address
consumption is rapidly increasing.
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IPv6 has a bright future.
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allow us to build a more robust and reliable
Internet.
simplify the implementation and deployment
of emergency response networks.
making our lives safer & more secure.