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IPv6IPv6

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IPv6:Why Do We Need a Larger Address Space?

•Internet population –Approximately over a billion users in November 2006

–Emerging population and geopolitical and address space •Mobile users

–PDA, tablet-PC, notepad, and so on –Approximately 20 million in 2004.

•Mobile phones –Already more than billion mobile phones delivered by the industry

•Transportation –1 billion automobiles forecast for 2008

–Internet access in planes – Example: Lufthansa •Consumer devices

– Sony mandated that all its products be IPv6-enabled by 2005 –Billions of home and industrial appliances

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IP v.6 Characteristics:• Larger address space- Global reachability and flexibility- Aggregation- Multihoming- Autoconfiguration- Plug-and-play- End to end without NAT- Renumbering

• Simpler header- Routing efficiency- Performance and forwarding- rate scalability- No broadcasts- No checksums- Extension headers- Flow labels- address renumbering and modification.

Mobility and security- Mobile IP & IPSec

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a- larger address space

IPv4• 32 bits or 4 bytes long~= 4,200,000,000 possible addressable nodes

IPv6128 bits address so no. of IPs = 2^128 possible IP

=3.4 * 10^38 possible IP =5 * 10^28 ip/human.

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b- Global reachability and flexibility:

-Quadrupling the available address space.

-Using unique IP for each device.

-IPv6 gives every user multiple global addresses that can be used for a wide variety of devices, including cell phones, personal digital assistants (PDAs), and IP-enabled vehicles.

- No need for NAT.

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• IP v.6 Format :1- Coloned Hexa decimal form. X : X : X : X : X : X : X : X FieldX = 4 hexa char. = 16 bits

2- Leading zeros in a field is optional.Ex: 2003:0001:X:X:X:X:X:X = 2003: 1 :X:X:X:X:X:X

3- Successive zeros in a field are represented as :0:Ex: 203B:0000:130F:0000:X:X:X:X= 203B: 0 :130F: 0 :X:X:X:X

4- Successive fields of zeros is represented by : : and can be used only once.

Ex: 203B:0000:0000:130F:0000:0000:0000:ABCD = 203B: 0 : 0 :130F: : ABCD

• If two “::” notations are placed in the address, there is no way to identify the size of each block of zeros.

= 203B: :130F: :ABCD => incorrect

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Examples:

1- FF01: 0 : 0 : 0 : 0 : 0 : 0 : 0001 => FF01::1

2- 0 : 0 : 0 : 0 : 0 : 0 : 0 : 1 => ::1

3- 0 : 0 : 0 : 0 : 0 : 0 : 0 : 0 => ::

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• Forms of IP v.6 destination address:

MulticastUnicast Anycast Broadcast

Any device from a certain group has to

receive the packet

Only one device has to

receive the packet

A complete groupof devices has to

receive the packet

Does not exist

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• Forms of IP v.6 destination address:1- Unicast:

Site localLink local Aggregate global

Address&

IPv4 mapped

loopback& unspecified

(::1/128)

public IP

Used within the local site (private add.)

uses with directly Connected device

(local protocol messages)(FE80::/10) )FEC0::/10(

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Link-Local Address

•Link-local addresses have a scope limited to the link and are dynamically created on all IPv6 interfaces by using a specific link-local prefix FE80::/10 and a 64-bit interface identifier.

•Link-local addresses are used for automatic address configuration, neighbor discovery, and router discovery. Link-local addresses are also used by many routing protocols.

•Link-local addresses can serve as a way to connect devices on the same local network without needing global addresses.

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IPv6 is defined on most of the current data link layers, including the following:

Ethernet* PPP*

High-Level Data Link Control (HDLC)* FDDI

Token Ring ATM**

Frame Relay***

*Cisco supports these data link layers. **Cisco supports only ATM permanent virtual circuit (PVC) and

ATM LAN Emulation ***Cisco supports only Frame Relay PVC.

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IPv6 Global Unicast (and Anycast) Addresses

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Interface Identifiers• Cisco uses the extended universal identifier (EUI)-64 format to do stateless autoconfiguration.• This format expands the 48-bit MAC address to 64 bits by inserting “FFFE” into the middle between the upper 3 bytes (Organizational Unique Identifier [OUI] field) and thelower 3 bytes (serial number) of the link layer address.

• To make sure that the chosen address is from a unique Ethernet MAC address, the universal/local (U/L bit) is set to 1 for global scope (0 for local scope), the seventh bit in the high-order byte is set to 1(equivalent to the IEEE G/L bit).

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2-MulticastThe multicast addresses, FF00:: to FF0F::, are reserved .

)Neighbor solicitation messages are sent on a local link when a node wants to determine the link-layer address of another node on the same local link, similar to Address Resolution Protocol [ARP]

in IPv4(.

MulticastMulticast

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3 -Anycast (Global unicast) Group of devices that have the same function, & packet should reach only one of the destinations.Routers decide on closest device to reach that destination.

• Characterized by: –One-to-nearest (allocated from unicast address space).

–Multiple devices share the same address. –All anycast nodes should provide uniform service.

–Suitable for load balancing and content delivery services.

Anycast addresses are syntactically indistinguishable from global unicast addresses because anycast addresses are allocated from the global unicast address space.

Note: Anycast addresses must not be used as the source address of an IPv6 packet.

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4 -Broadcast -Not supported by IP v6.

Note: A single interface may be assigned multiple IPv6 addresses of any type: unicast, anycast, or multicast.

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C- Address Aggregation

2001:0410/::32

/32

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Stateless DHCP for IPv6 is also called “DHCP-lite .”

D- Plug and PlayThis is done through-Stateless Auto configuration (Getting a logical address)

-RenumberingGetting new addressing scheme

-What is my link address)Router Solicitation(

)Router Advertisement(

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E- Integrated Mobile IP & Integrated security features

IP v6 uses Mobile IP & IPsec as a mandatory protocol to provide end to end security.

The new headers for IPv6 contain fields for Mobile IP & IPSec.

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F- Simpler headerIP v.6 packet is simpler than IP v.4. (no fragmentation field).

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• IP routing protocols supporting IPv6 and their IOS release:– Integrated IS-IS for IPv6 – Release 12.0(22)S and 12.2(8)T– BGP extensions for IPv6 – Release 12.0(22)S and 12.2(2)T– RIP for IPv6 – Release 12.0(22)S and 12.2(2)T– Static routes – Release 12.0(22)S and 12.2(2)T– EIGRP for IPv6– OSPF for IPv6

G-IPv6 Routing Protocols

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Configuring IPv6:(config)#ipv6 unicast-routing(config)#ipv6 route <prefix> <prefix length> {interface / next hop ip}(config)#interface fa0/0(config-if)#ipv6 address <address> </ prefix length > [eui-64]The eui-64 parameter forces the router to complete the address low-order 64-bits by using an EUI-64 interface ID.Example:

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H-Transition richness to IP v.6:

• Transition richness means:– No fixed day to convert, no need to convert all at once – Different transition mechanisms are available

• Use of dual stack or 6-to-4 tunnels– Different compatibility mechanisms

IPv4 and IPv6 nodes can communicate.1 (By using Dual stack

2 (6-to-4 tunneling or “IPv6 over IPv4 ”3 (NAT-PT

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1) IOS Dual StackDual stack is an integration method where a node has

implementation and connectivity to both an IPv4 and IPv6 network.

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2) Cisco IOS is IPv6-ready:– If IPv4 and IPv6 are configured on an interface, This interface is dual-

stacked

-Overlay Tunnels

– Tunneling encapsulates the IPv6 packet in the IPv4 packet. IPv4 protocol 41

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3) NAT (Network Address Translation) – (Protocol Translation)For legacy equipment that will not be upgraded to IPv6 and for some deployment scenarios, techniques that can connect IPv4-only nodes on IPv6-only nodes are available. Translation is basically an extension of NAT techniques.

This mapping can be obtained dynamically from the DNS server.