ccna lec ipv6

1© 2001, Cisco Systems, Inc. All rights reserved.© 2003, Cisco Systems, Inc.

IPv6 Needs & Applications

222© 2003, Cisco Systems, Inc.

With millions of new devices becoming IP aware, With millions of new devices becoming IP aware, the need for increased addressing and plug & play networking the need for increased addressing and plug & play networking

is only met with the implementation of IPv6is only met with the implementation of IPv6

IP – The Application’s Convergence Layer

EthernetEthernet

Optical

Optical

E-Power

E-Power

Wireless

Wireless

Storage Storage C

hannelC

hannel

CA

TVC

ATV

PP SS DN

DN

xDSL

xDSL

IP version 6IP version 6

More t o

More t o

Com

eC

ome


IPv6 Protocol• Headers and fields

Version IHL Type of Service Total Length

Identification Flags Fragment Offset

Time to Live Protocol Header Checksum

Source Address

Destination Address

Options Padding

Version Traffic Class Flow Label

Payload Length Next Header Hop Limit

Source Address

Destination Address

IPv4 HeaderIPv4 Header IPv6 HeaderHeader

- field’s name kept from IPv4 to IPv6

- fields not kept in IPv6

- Name & position changed in IPv6

- New field in IPv6

Global Routing Prefix

Global IPv6 Address Structure

Interface IDSubnet ID

128 Bits

Network Portion Host Portion

48 Bits 16 Bits 64 Bits

•Interface ID – identifies a host interface address

•Subnet ID – 65,536 possible subnets

•Global Routing Prefix – issued by IANA or RIR to ISPs at /32 or /35 in length, ISPs then issue to customers with /48 mask

•Provides 340,282,366,920,938,463,463,374,607,431,770,000,000 Addresses....

Rick Graziani [email protected] 15

Rule 1: Leading 0’s

3ffe : 1944 : 0100 : 000a : 0000 : 00bc : 2500 : 0d0b3ffe : 1944 : 100 : a : 0 : bc : 2500 : d0b



Practice

3ffe : 0404 : 0001 : 1000 : 0000 : 0000 : 0ef0 : bc00

3ffe : 0000 : 010d : 000a : 00dd : c000 : e000 : 0001

ff02 : 0000 : 0000 : 0000 : 0000 : 0000 : 0000 : 0005



Practice

3ffe : 0404 : 0001 : 1000 : 0000 : 0000 : 0ef0 : bc003ffe : 404 : 1 : 1000 : 0 : 0 : ef0 : bc00

3ffe : 0000 : 010d : 000a : 00dd : c000 : e000 : 00013ffe : 0 : 10d : a : dd : c000 : e000 : 1

ff02 : 0000 : 0000 : 0000 : 0000 : 0000 : 0000 : 0005 ff02 : 0 : 0 : 0 : 0 : 0 : 0 : 5


Rule 2: Double colon :: equals 0000…0000

ff02 : 0000 : 0000 : 0000 : 0000 : 0000 : 0000 : 0005 ff02 : 0 : 0 : 0 : 0 : 0 : 0 : 5 ff02 : : 5

ff02::5



• Only a single contiguous string of all-zero segments can be represented with a double colon.

Example: Both of these are correct

2001 : 0d02 : 0000 : 0000 : 0014 : 0000 : 0000 : 00952001 : d02 :: 14 : 0 : 0 : 95 OR2001 : d02 : 0 : 0 : 14 :: 95

2001 : d02 :: 14 : 0 : 0 : 952001 : d02 : 0 : 0 : 14 :: 95



2001:d02::14::95

2001:0d02:0000:0000:0014:0000:0000:00952001:0d02:0000:0000:0000:0014:0000:00952001:0d02:0000:0014:0000:0000:0000:0095


Network Prefixes

• IPv4, the prefix—the network portion of the address—can be identified by a dotted decimal or hexadecimal address mask or a bitcount.

255.255.255.0 or /24

• IPv6 prefixes are always identified by bitcount. • The address is followed by a forward slash and a decimal

number indicating how many of the first bits of the address are the prefix bits.

3ffe:1944:100:a::/64


Addressing

• UnicastLike IPv4 this address is used for uniquely identifying an IPv6 node. Packet identified by the destination unicast address is delivered to the router connecting to the specified interface

• Mulitcast

Packet sent to group of interfaces, packet sent to this address is sent to the group of nodes in a given scope.

• AnycastCommon address assigned to multiple interfaces, packet is sent to the closest interface to the source as defined by the routing table

• A single interface may be assigned multiple IPv6 addresses of any type (Unicast, Anycast, Multicast)

No Broadcast Address -> Use Multicast

- One to Nearest- Redundancy / Backup

29

64 Bits Interface ID

Static IPv6 Address Assignment

R1 R2Fa0/0

Fa0/0

R1(config)#interface fa0/0 R1(config-if)#ipv6 address 2001:1::1/64R1(config-if)#ipv6 address 2002:1::1/64

R1#show run interface fa0/0

interface FastEthernet0/0 ip address 10.10.10.1 255.255.255.0 duplex auto speed auto ipv6 address 2001:1::1/64 ipv6 address 2002:1::1/64

R1#(config) ipv6 unicast-routingR1# (config) int fa 0/0R1# (config-if) ipv6 enableR1# (config-if) ipv6 address 2001::1/64

R2#(config) ipv6 unicast-routingR2# (config) int fa 0/0R2# (config-if) ipv6 enableR2# (config-if) ipv6 address autoconfig

IPv6 Address Auto-Configuration


R1# (config) int fa 0/1R1# (config-if) ipv6 enableR1# (config-if) ipv6 address 2002::1/64

R1# (config) ipv6 route 2003::1/64 2001::2


R2# (config) int fa 0/1R2# (config-if) ipv6 enableR2# (config-if) ipv6 address 2003::1/64

R2# (config) ipv6 route 2002::1/64 2001::1

R1#(config) ipv6 unicast-routingR1# (config) int fa 0/0R1# (config-if) ipv6 enableR1# (config-if) ipv6 address 2001::1/64R1#(config-if) ipv6 rip 1 enableR1# (config) int fa 0/1R1# (config-if) ipv6 enableR1# (config-if) ipv6 address 2002::1/64R1# (config-if) ipv6 rip 1 enable

R2#(config) ipv6 unicast-routingR2# (config) int fa 0/0R2# (config-if) ipv6 enableR2# (config-if) ipv6 address 2001::2/64R2# (config-if) ipv6 rip 1 enableR2# (config) int fa 0/1R2# (config-if) ipv6 enableR2# (config-if) ipv6 address 2003::1/64R2# (config-if) ipv6 rip 1 enable

R1#(config) ipv6 unicast-routingR1#(config) ipv6 router ospf 1R1#(config-router) router-id 11.1.1.1R1# (config) int fa 0/0R1# (config-if) ipv6 enableR1# (config-if) ipv6 address 2001::1/64R1#(config-if) ipv6 ospf 1 area 0R1# (config) int fa 0/1R1# (config-if) ipv6 enableR1# (config-if) ipv6 address 2002::1/64R1# (config-if) ipv6 ospf 1 area 0

R2#(config) ipv6 unicast-routingR2#(config) ipv6 router ospf 1R2#(config-router) router-id 22.2.2.2R2# (config) int fa 0/0R2# (config-if) ipv6 enableR2# (config-if) ipv6 address 2001::2/64R2# (config-if) ipv6 opsf 1 area 0R2# (config) int fa 0/1R2# (config-if) ipv6 enableR2# (config-if) ipv6 address 2003::1/64R2# (config-if) ipv6 ospf 1 area 0

Chapter 8b

IPv4/IPv6 Transition Techniques•A wide range of techniques are available for the

period of transition between IPv4 and IPv6. These techniques can be grouped into the following three categories:

•Dual-stack techniques: Hosts and network devices run both IPv4 and IPv6 at the same time.

•Tunnelling techniques: Isolated IPv6 networks are connected over an IPv4 infrastructure using tunnels.

•Translation techniques: A translation device converts IPv6 packets into IPv4 packets and vice versa.

Chapter 8b

IPv4/IPv6 Dual Stack

R1 R2S0/1/0

S0/1/02001:1::2/6410.10.10.2/30

2001:1::1/6410.10.10.1/30

Lo 101 – 11::11:1/64

Lo 100 – 10::10:1/6410.10.20.1/24

Lo 102 – 13::13:1/6410.10.30.1/24

•Dual stack is one of the primary technologies that makes the transition to IPv6 possible. •It is an integration method in which a node has connectivity to both an IPv4 and IPv6 network; thus the node has two protocol stacks. •The two stacks can be on the same interface or on multiple interfaces.•A dual-stack node chooses which stack to use based on destination address; the node should prefer IPv6 when available.

Chapter 8b

IPv4/IPv6 Tunnelling

IPv6 Network

IPv4 Network

IPv6 Network

IPv6 Header IPv6 Data IPv6 Header IPv6 Data

IPv6 Header IPv6 DataIPv4 Header

Dual-StackRouter

Dual-StackRouter

IPv6 Host IPv6 Host

IPv4 Network

IPv4 Network

Dual-StackRouter

Dual Stack Host

IPv6 Host

•Tunnels are often used in networking to overlay incompatible functions over an existing network - For IPv6, tunnelling, an IPv6 packet is encapsulated within IPv4.

•When tunnelling IPv6 traffic over an IPv4 network, an edge device (such as a router) encapsulates the IPv6 packet inside an IPv4 packet and the device at the other edge de-encapsulates it, and vice versa.

Chapter 8b

R2:Int tunnel 1Ipv6 enableIpv6 address 2006::1/64Ipv6 ospf 1 area 0Tunnel source ser 1/0Tunnel destination 1.1.1.2Tunnel mode ipv6ip

R3:Int tunnel 1Ipv6 enableIpv6 address 2006::2/64Ipv6 ospf 1 area 0Tunnel source ser 1/0Tunnel destination 1.1.1.1Tunnel mode ipv6ip

TRANSITION STRATEGY – TUNNELLING

Chapter 8b

IPv4/IPv6 Translation

IPv6 Network

IPv4 Network

2001::10:1/64 2001::20:1/64

NAT-PTDeviceSource Destination

192.168.30.1 192.168.2.2

Source Destination

Host A 2001::10:1/64

Host B 192.168.30.1

•For legacy equipment that will not be upgraded to IPv6 and for some deployment scenarios, techniques are available for connecting IPv4-only nodes to IPv6-only nodes, using translation, an extension of NAT techniques.

•NAT-PT is a translation mechanism that sits between an IPv6 network and an IPv4 network.

•The job of the translator is to translate IPv6 packets into IPv4 packets and vice versa; it is more than an address translator, it is really a protocol translator.

Multicast Prefix

IPv6 Multicast Address Structure

Group IDScope

8 Bits 4 Bits 112 Bits

Flags

4 Bits

Address Multicast GroupFF02::1 All NodesFF02::2 All RoutersFF02::5 OSPFv3

RoutersFF02::6 OSPFv3 DRsFF02::9 RIPng RoutersFF02::A EIGRP RoutersFF02::D All PIM

Routers

•A multicast address identifies not one device but a set of devices – a multicast group.

•A packet being sent to a multicast group is originated by a single device – a multicast packet has a unicast address as its source and a multicast address as its destination.

•Multicast is essential to the basic operation of IPv6, particularly some of its plug-and-play features such as neighbour discovery and autoconfiguration.

ccna lec ipv6

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