IPv6 – part I.FUNDAMENTALS AND PROTOCOLS / ICND 1

IPv4 vs. IPv6 Header

IPv4 vs. IPv6 Features

IPv6 benefits

More efficient routing;

Quality of service (QoS)

Elimination of the NAT requirement

Network Layer security with end-to-end IPsec

Ease of management using stateless address autoconfiguration

Improved header format to reduce header overhead.

IPv6 Addressing

IPv6 address = 128b Unknown address ::/128

Loopback address ::1

Link-local address FE80::/10

Site-local address FEC0::/10 – deprecated

Unique local FD00::/8

Global address All otherwise not reserved, ie. 2000::/3

Multicast address FF00::/8

Anycast address

Link-local address

Unique only on individual link. Link-local addresses are never routable!

Unique local address

Prefix FD00::/8

Similar to privite IPv4 addresses

Not registered globaly like Global Unicast addresses

FD [8b] + Global ID [40b] + Subnet [16b] + Interface ID [64b]

Not routed over public Internet

Multicast address

Multicast address is an indetifier for a group of nodes

What‘s the difference to Broadcast? Broadcast packets are not routable, and every node on a subnet

must process them.

In IPv6 ICMPv6 messages - MLD (Multicast Listener Discovery) are used for Multicast group management

Anycast address

Anycast address can be assigned to multiple nodes in the group

Routing protocol takes a decision to route a packet to nearest node

What‘s the difference to Multicast? Multicast – all nodes in the group process the packet

Global unicast address

Routed over public Internet, globally unique

Assigned by registered authorities (IANA, RIR, LIR)

IPv6 global address 2001:DEAD:BEEF::/48

2001:DEAD:BEEF:0001::/64

2001:DEAD:BEEF:0001:0000:0000:0000:0001 = 2001:DEAD:BEEF:1::1/128

IPv6 Protocols

OSPF upgraded to version 3

ICMP upgraded to ICMPv6

ARP replaced by NDP

ICMPv6

performs error reporting, diagnostic functions

Message types Destination unreachable

Time exceeded

Echo request, reply

NDP

Router advertisement, Router solicitation, Neighbor advert., Neighbor sol.

…

Neighbor Discovery Protocol

Layer 2 protocol

Responsible for address autoconfiguration of nodes

discovery of other nodes on the link

determining the Link Layer addresses of other nodes

duplicate address detection

finding available routers

EUI-64 format

IPv6 routing protocols

IPv4 RIPv2, OSPFv2, EIGRP, BGP, ISIS

IPv6 RIPng, OSPFv3, EIGRPv6, BGP, ISIS

Other IPv6 features

Stateless autoconfiguration

Statefull autoconfiguration DHCPv6