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IPv6
INTRODUCTION
INTRODUCTION
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…)
IPv6 was adopted because:– 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…)
3 types of address:– Unicast addressing– Multicast addressing– Anycast addressing
Additional fields included in IPv6 header– priority field, flow field.
IPv6 is a natural increment to IPv4.
IPv6
NEW CHANGES IN IPv6
New changes in IPv6
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.
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.
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.
IPv6
IPv6 HEADER
Introduction
more simpler efficient reduce process cost
Base Header
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
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
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
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 headerNext header= TCP
TCP segment
Basic headerNext header= routing
Routing headerNext header= fragment
FragmentheaderNext header=authentication
Authentication HeaderNext header=TCP
TCP segment
TYPES OF EXTENSION HEADERS
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
Implement an efficient method to alert routers of a packet that requires special processing.
ROUTING HEADER
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
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
Otherwise, the source must limit all packets to 1280 octets(the minimum MTU that must be supported by each network).
AUTHENTICATION HEADER
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
For packets that must be sent secretly. Provide confidentiality and privacy.
DESTINATION OPTION HEADER
optional information to be examined by the destination node.
Not use during routing.
IPv6
IPv6 ADDRESSING
Brief Introduction
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:
– Unicast– Anycast– Multicast
Unicast Address
Corresponds to a single computer The format is:
010 Registry Provider Subscriber Subnet Interface
Unicast Address
3 types of Unicast Address– Global unicast
– Site-local unicast it is designed to used for addressing inside of a site
without the need for a glocal prefix
n bits m bits 128 – n – m – bits
Global Routing Prefix Subnet Id Interface ID
10 bits 54 bits 64 bits
1111111011 Subnet ID Interface ID
Unicast Address
– Link - local unicast 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
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
A longest prefix P identifies the topological region in which all interfaces belonging to that anycast address reside.
Within the region identified by P, the anycast address must be maintained as a separate entry in the routing system
Outside the region identified by P, the anycast address may be aggregated into the routing entry for prefix P.
Multicast Address
Pre-defined Multicast addresses– 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
FF00:0:0:0:0:0:0:0FF01:0:0:0:0:0:0:0FF02:0:0:0:0:0:0:0FF03:0:0:0:0:0:0:0FF04:0:0:0:0:0:0:0FF05:0:0:0:0:0:0:0FF06:0:0:0:0:0:0:0FF07:0:0:0:0:0:0:0FF08:0:0:0:0:0:0:0FF09:0:0:0:0:0:0:0FF0A:0:0:0:0:0:0:0FF0B:0:0:0:0:0:0:0FF0C:0:0:0:0:0:0:0FF0D:0:0:0:0:0:0:0FF0E:0:0:0:0:0:0:0FF0F:0:0:0:0:0:0:0
Multicast Address
All nodes addresses – 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
All routers addresses – 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
Solicited-Nodes Address: – 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
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
Colon Hexadecimal Notation– 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
Zero Compression– 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
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
CIDR Notation. – 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
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.
IPv6 has a bright future.– 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.