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IPv6 - Introduction
Michael DirskaHasso-Plattner-Institut Potsdam
04/2004 -md- 2
Why a new protocol version?
• Beginning of 1990s: – Help! - IPv4 address space is running out– There are too few Class-B-Networks left– Routing Tables are growing immensely
04/2004 -md- 3
IPv4 address structure (old)
• 32 Bit• Written as 4 Bytes, decimal, "." inbetween• Netmasks: number of relevant bits
0 Class A /8 12.x.x.x
10 Class B /16 141.89.x.x
110 Class C /24 192.168.1.x
1110 Class D Multicast
1111 Class E (nicht belegt)
04/2004 -md- 4
IPv4 address structure (new)
• Classless Inter-Domain Routing (CIDR)
• RFC 1519 September 1993
• (www.cidr-report.org)
0 Unicast-Adressen /8 bis /24-Netze
10 "
110 "
1110 Multicast
1111 (nicht belegt)
04/2004 -md- 5
Internet-Routing
Uni Potsdam141.89.0.0/16
HU Berlin141.20.0.0/16
DFN G-WiNAS680
WIDE Project203.178.136.0/21
AS2500
04/2004 -md- 6
IP: Next Generation (IPng)
• Dec. 1993: RFC 1550Request for White Papers
• lots of answers August 1994, examples:– RFC 1669
"Market Viability as a IPng Criteria"– RFC 1671
"IPng White Paper on Transition"– RFC 1687
"A Large Corporate User's View of IPng"
04/2004 -md- 7
IPng renamed to IPv6
• Jan. 1995: RFC 1752"The Recommendation for the IP Next Generation Protocol"
• Dec. 1995: RFC 1883"Internet Protocol, Version 6 (IPv6) Specification"
04/2004 -md- 8
Decision in favour of a new address space
• IPv6 has 128-Bit addresses (millions of addresses per square meter of the earths surface)
• the new version solves old problems (fragmentation) and keeps the IP-header small
• elegant solution – technically!
• but: how do you switch from IPv4 to IPv6? Do we switch at all? Can both protocols co-exist?
04/2004 -md- 9
Advantages of a new address space
• We can learn from the mistakes:– better address allocation (smaller routing tables)– enough global routable addresses even for the
smallest imaginable devices
04/2004 -md- 10
Disadvantages of a new address space
• all connections between Autonomous Systems (AS) must be re-negotiated
• lots of work to setup a second infrastructure
• there is no „killer application“ in sight – so why do we want it?
• see: D.Bernstein "IPv6-mess"
04/2004 -md- 11
current IPv6 specifications
• RFC 2460"Internet Protocol, Version 6 (IPv6) Specification"
• RFC 2461"Neighbor Discovery for IP Version 6 (IPv6)"
• RFC 2462"IPv6 Stateless Address Autoconfiguration"
• RFC 2463"Internet Control Message Protocol (ICMPv6)"
04/2004 -md- 12
IPv4 header
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Version| IHL |Type of Service| Total Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Identification |Flags| Fragment Offset | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Time to Live | Protocol | Header Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Destination Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Options | Padding | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
from RFC 791
04/2004 -md- 13
IPv6 header +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Version| Traffic Class | Flow Label | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Payload Length | Next Header | Hop Limit | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + Source Address + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + Destination Address + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ from RFC 2460
04/2004 -md- 14
IPv6 Adress-Struktur
• 128 Bit• written as 8*16 Bit, hexadecimal• : inbetween
2001:0DB8:0010:0000:0000:0000:0000:0001
2001:0DB8:10::1
FF02::1
FE80::192.168.111.40 = FE80::C0A8:6F28
2001:DB8::/32
::1
::FFFF:192.168.111.40
04/2004 -md- 15
IPv6 address structure Allocation Prefix Fraction of (binary) Address Space ----------------------------------- -------- ------------- Unassigned (see Note 1 below) 0000 0000 1/256 Unassigned 0000 0001 1/256 Reserved for NSAP Allocation 0000 001 1/128 [RFC1888] Unassigned 0000 01 1/64 Unassigned 0000 1 1/32 Unassigned 0001 1/16 Global Unicast 001 1/8 [RFC2374] Unassigned 010 1/8 Unassigned 011 1/8 Unassigned 100 1/8 Unassigned 101 1/8 Unassigned 110 1/8 Unassigned 1110 1/16 Unassigned 1111 0 1/32 Unassigned 1111 10 1/64 Unassigned 1111 110 1/128 Unassigned 1111 1110 0 1/512 Link-Local Unicast Addresses 1111 1110 10 1/1024 Site-Local Unicast Addresses 1111 1110 11 1/1024 Multicast Addresses 1111 1111 1/256
aus RFC 3513
04/2004 -md- 16
global IPv6 adresses
0010 3
IANA RIR
RIR LIR
LIR Customer
23 35 48Interface ID
64 128
64 bit for local configuration(auto-configuration)
04/2004 -md- 17
weitere IPv6-Adresstypen
FE80::/640
Interface ID64 128
Link Local
04/2004 -md- 18
Interface Identifier
|0 1|1 3|3 4| |0 5|6 1|2 7| +----------------+----------------+----------------+ |cccccc0gcccccccc|ccccccccmmmmmmmm|mmmmmmmmmmmmmmmm| +----------------+----------------+----------------+
aus RFC2373
|0 1|1 3|3 4|4 6| |0 5|6 1|2 7|8 3| +----------------+----------------+----------------+----------------+ |cccccc1gcccccccc|cccccccc11111111|11111110mmmmmmmm|mmmmmmmmmmmmmmmm| +----------------+----------------+----------------+----------------+
FF FEXOR 0x0200
IEEE 802 48 bit MAC
04/2004 -md- 19
IPv6 network
node
node
node
linklink
link
link node
node
host host
host
router
router
Interface
FE80::/64
FE80::/64
04/2004 -md- 20
Stateless Address Autoconfiguration (RFC2462)
• is always used for link-local addresses
• can be used to configure global adresses
• Duplicate Address Detection should be performed on the link
04/2004 -md- 21
Neighbor Discovery (RFC2641)
• Duplicate Address Detection
• Router Discovery
• Address Autoconfiguration
• Next-hop Determination
• Address Resolution
• Neighbor Unreachability Detection
• Redirect
04/2004 -md- 22
Neighbor Discovery
• five message types (in ICMPv6)– Router Discovery– Router Solicitation– Neighbor Discovery– Neighbor Solicitation– Redirect
• Why ICMPv6? You can use AH...
04/2004 -md- 23
transition to IPv6
t1996 20??
IPv4IPv6
2020 ?2030 ?
Es wird lange Zeit gleichzeitige IPv4- und IPv6-Konnektivitätgeben müssen.
04/2004 -md- 24
IPv4 Netzwerk
node
node
node
link
node
host host
host
router
IPv4 Internet
04/2004 -md- 25
dual stack
node
node
node
link
node
host host
host
IPv4 routerIPv4 Internet
node
IPv6 router
node
host
IPv6 Internet
04/2004 -md- 26
configured tunnel
node
node
node
link
node
host host
host
IPv4 routerIPv4 Internet
node
IPv6 router
node
host
IPv6 Internettunnel broker
node
IPv6-over-IPv4tunnel
04/2004 -md- 27
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . : IP Address. . . . . . . . . . . . : 141.89.224.145 Subnet Mask . . . . . . . . . . . : 255.255.255.0 IP Address. . . . . . . . . . . . : fe80::208:2ff:fe5e:7afd%7 Default Gateway . . . . . . . . . : 141.89.224.1
Tunnel adapter Teredo Tunneling Pseudo-Interface:
Connection-specific DNS Suffix . : IP Address. . . . . . . . . . . . : fe80::5445:5245:444f%8 Default Gateway . . . . . . . . . :
Tunnel adapter 6to4 Tunneling Pseudo-Interface:
Connection-specific DNS Suffix . : IP Address. . . . . . . . . . . . : 2002:8d59:e091::8d59:e091 Default Gateway . . . . . . . . . : 2002:c058:6301::c058:6301 2002:836b:213c::836b:213c
Tunnel adapter Automatic Tunneling Pseudo-Interface:
Connection-specific DNS Suffix . : IP Address. . . . . . . . . . . . : fe80::5efe:141.89.224.145%2 Default Gateway . . . . . . . . . :
Windows XP