IPv 6 Internet Protocol Version 6 Internet Protocol

IPv 6 Internet Protocol Version 6

Internet Protocol Version 6 (IPv 6) • • IPv 6 solutions to IPv 4 disadvantages IPv 6 addressing IPv 6 header DNS support for IPv 6 Core protocols of IPv 6 Neighbor Discovery Differences between IPv 4 and IPv 6 2/24 Groep T Leuven – Information department 2003 -2004 - Information management 2

Disadvantages of IPv 4 • • • Limited address space Flat routing infrastructure Configuration Security Quality of service (Qo. S) Mobility 3/24 Groep T Leuven – Information department 2003 -2004 - Information management 3

IPv 6 Solutions to IPv 4 Disadvantages • • • Huge address space Hierarchical routing infrastructure Automatic configuration Built-in security Better support for Qo. S Built-in mobility 4/24 Groep T Leuven – Information department 2003 -2004 - Information management 4

Larger Address Space IPv 4 • 32 bits or 4 bytes long ~ = 4, 200, 000 possible addressable nodes IPv 6 • 128 bits or 16 bytes: four times the bits of IPv 4 ~ = 3. 4 * 1038 possible addressable nodes ~ = 340, 282, 366, 920, 938, 463, 374, 607, 432, 768, 211, 456 28 ~ = 5 * 10 addresses person 5/24 Groep T Leuven – Information department 2003 -2004 - Information management 5

IPv 6 Adressing 6. 5 Billion people on earth Typical braincell has ~100 Billion cells (your count may vary) 6/24 Groep T Leuven – Information department IPv 6 addresses person IPv 6 addresses for every human brain cell on the planet 2003 -2004 - Information management 6

Larger Address Space Enables Address Aggregation • Aggregation of prefixes announced in the global routing table • Efficient and scalable routing • Improved bandwidth and functionality for user traffic 7/24 Groep T Leuven – Information department 2003 -2004 - Information management 7

The IPv 6 Address Space • 128 -bit address space • 128 bits were chosen to allow multiple levels of hierarchy and flexibility in designing hierarchical addressing and routing • Global unicast and anycast addresses are defined by a global routing prefix, a subnet ID, and an interface ID 8/24 Groep T Leuven – Information department 2003 -2004 - Information management 8

IPv 6 Address Representation • x: x: x, where x is a 16 -bit hexadecimal field • Leading zeros in a field are optional: – 2031: 0: 130 F: 0: 0: 9 C 0: 876 A: 130 B • Successive fields of 0 can be represented as : : , but only once per address. Examples: 2031: 0000: 130 F: 0000: 09 C 0: 876 A: 130 B 2031: 0: 130 f: : 9 c 0: 876 a: 130 b FF 01: 0: 0: 0: 1 >>> FF 01: : 1 0: 0: 1 >>> : : 1 0: 0: 0 >>> : : 9/24 Groep T Leuven – Information department 2003 -2004 - Information management 9

Compressing Zeros • Some IPv 6 addresses contain long sequences of zeros • A single contiguous sequence of 16 -bit blocks set to 0 can be compressed to “: : ” (double-colon) • Examples: – FE 80: 0: 2 AA: FF: FE 5 F: 47 D 1 becomes FE 80: : 2 AA: FF: FE 5 F: 47 D 1 – FEC 0: 0: 0: 41 CD: 2 AA: FF: FE 5 F: 47 D 1 becomes FEC 0: : 41 CD: 2 AA: FF: FE 5 F: 47 D 1 – FF 02: 0: 0: 0: 1 (a multicast address) becomes FF 02: : 1 10/24 Groep T Leuven – Information department 2003 -2004 - Information management 10

IPv 6 Prefixes • Prefix is the part of the address where the bits have fixed values or are the bits of a route or subnet identifier • IPv 6 subnets or routes always uses address/prefix-length notation – CIDR notation • Examples: – 3 FFE: FFFF: 2 A: 41 CD: : /64 is a subnet identifier – 3 FFE: FFFF: 2 A: : /48 is a route – FF: : /8 is an address range 11/24 Groep T Leuven – Information department 2003 -2004 - Information management 11

Types of IPv 6 Addresses • Unicast – Address of a single interface – One-to-one delivery to single interface • Multicast – Address of a set of interfaces – One-to-many delivery to all interfaces in the set • Anycast – Address of a set of interfaces – One-to-one-of-many delivery to a single interface in the set that is closest • No more broadcast addresses 12/24 Groep T Leuven – Information department 2003 -2004 - Information management 12

Unicast IPv 6 Addresses • Global addresses – Used on IPv 6 Internet – Equivalent to IPv 4 public addresses • Local-Use Addresses – Site-local addresses • Equivalent to IPv 4 private addresses • Always begin with FEC 0 – Link-local addresses • Equivalent to APIPA Global addresses • Always begin with FE 80 13/24 Groep T Leuven – Information department Site Local 2003 -2004 - Information management Link Local 13

IPv 6 Interface Identifiers • Based on: – Derived from the MAC address of the network adapter to which the address is assigned – Randomly generated to provide IPv 4 -equivalent anonymity – Assigned during a Point-to-Point Protocol (PPP) connection – Assigned during DHCP configuration 14/24 Groep T Leuven – Information department 2003 -2004 - Information management 14

IPv 6 Interface identifier EUI-64 • 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 16 bits. • 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). Mac address 48 bit 00 90 27 17 FC 0 F 64 bit 00 90 27 FF FE 17 FC 0 F 000000 U 0 U= 1 = Unique 0 = Not Unique 02 90 27 FF FE 17 FC 0 F 15/24 Groep T Leuven – Information department 2003 -2004 - Information management 15

IPv 6 Header IPv 4 Header Version IHL Type of Service Identification Time to Live Protocol IPv 6 Header Total Length Flags Fragment Offset Header Checksum Version Traffic Class Payload Length Flow Label Next Header Hop Limit Source Address Destination Address Legend Options Padding Source Address Field’s Name Kept from IPv 4 to IPv 6 Fields Not Kept in IPv 6 Name and Position Changed in IPv 6 Destination Address New Field in IPv 6 16/24 Groep T Leuven – Information department 2003 -2004 - Information management 16

IPv 6 Extension Header types • • • Routing Header Fragmentation Header Hop-by-Hop Options Header Destinations Options Header Authentication Header Encrypted Security Payload Header Ethernet header IPv 6 header Routing header 17/24 Groep T Leuven – Information department Frag header Auth header ESP header TCP header Application data 2003 -2004 - Information management 17

DNS Support for IPv 6 • AAAA resource records for name-to-address resolutions • PRT resource records in the IP 6. ARPA reverse domain for address-to-name resolutions 18/24 Groep T Leuven – Information department 2003 -2004 - Information management 18

Core Protocols of IPv 6 • IPv 6 – Replacement for IPv 4 • ICMPv 6 – Replacement for ICMP for IPv 4 • Neighbor Discovery – Replacement for ARP, Redirect, and Router Discovery for IPv 4 • Multicast Listener Discovery – Replacement for IGMPv 2 for IPv 4 19/24 Groep T Leuven – Information department 2003 -2004 - Information management 19

IPv 6 Neighbor Discovery • Messages – Neighbor Solicitation – Neighbor Advertisement – Router Solicitation – Router Advertisement – Redirect • Processes – Address resolution – Duplicate address detection – Router discovery – Redirect – Neighbor unreachability detection 20/24 Groep T Leuven – Information department 2003 -2004 - Information management 20

Stateless Autoconfiguration • A router sends network information to all the nodes on the local link. • A host can autoconfigure itself by appending its IPv 6 interface identifier (64 -bit format) to the local link prefix (64 bits). • The result is a full 128 -bit address that is usable and guaranteed to be globally unique. 21/24 Groep T Leuven – Information department 2003 -2004 - Information management 21

A Standard Stateless Autoconfiguration • Stage 1: The PC sends a router solicitation to request a prefix for stateless autoconfiguration. 22/24 Groep T Leuven – Information department 2003 -2004 - Information management 22

A Standard Stateless Autoconfiguration (Cont. ) • Stage 2: The router replies with a router advertisement. 23/24 Groep T Leuven – Information department 2003 -2004 - Information management 23

Differences Between IPv 4 and IPv 6 Feature IPv 4 IPv 6 Address length 32 bits 128 bits Header size 20 -60 bytes 40 bytes IPSec support Optional Required Qo. S support Some Better Fragmentation Hosts and routers Hosts only Checksum in header Yes No Options in header Yes No Link-layer address resolution ARP (broadcast) Multicast Neighbor Discovery Messages Multicast membership IGMP Multicast Listener Discovery (MLD) Router Discovery Optional Required Uses broadcasts? Yes No Configuration Manual, DHCP Automatic, DHCP DNS name queries Uses A records Uses AAAA records DNS Groepreverse T Leuven –queries Information department 24/24 Uses IN-ADDR. ARPA Uses IP 6. ARPA 2003 -2004 - Information management 24