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IPv6 - Introduction. Michael Dirska Hasso-Plattner-Institut Potsdam. 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. IPv4 address structure (old). 32 Bit
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IPv6 - Introduction Michael Dirska Hasso-Plattner-Institut Potsdam
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
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)
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)
Internet-Routing AS2500 WIDE Project 203.178.136.0/21 AS680 DFN G-WiN Uni Potsdam 141.89.0.0/16 HU Berlin 141.20.0.0/16
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"
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"
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?
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
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"
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)"
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
IPv6 header +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Version| Traffic Class | Flow Label | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Payload Length | Next Header | Hop Limit | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + Source Address + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + Destination Address + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ from RFC 2460
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
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
IANA RIR RIR LIR LIR Customer global IPv6 adresses 0 3 23 35 48 64 128 001 Interface ID 64 bit for local configuration (auto-configuration)
weitere IPv6-Adresstypen Link Local 0 64 128 FE80::/64 Interface ID
Interface Identifier IEEE 802 48 bit MAC |0 1|1 3|3 4| |0 5|6 1|2 7| +----------------+----------------+----------------+ |cccccc0gcccccccc|ccccccccmmmmmmmm|mmmmmmmmmmmmmmmm| +----------------+----------------+----------------+ |0 1|1 3|3 4|4 6| |0 5|6 1|2 7|8 3| +----------------+----------------+----------------+----------------+ |cccccc1gcccccccc|cccccccc11111111|11111110mmmmmmmm|mmmmmmmmmmmmmmmm| +----------------+----------------+----------------+----------------+ FF FE XOR 0x0200 aus RFC2373
link link link link IPv6 network host router node node FE80::/64 router node FE80::/64 Interface node node host host
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
Neighbor Discovery (RFC2641) • Duplicate Address Detection • Router Discovery • Address Autoconfiguration • Next-hop Determination • Address Resolution • Neighbor Unreachability Detection • Redirect
Neighbor Discovery • five message types (in ICMPv6) • Router Discovery • Router Solicitation • Neighbor Discovery • Neighbor Solicitation • Redirect • Why ICMPv6? You can use AH...
transition to IPv6 IPv6 IPv4 1996 20?? t 2020 ? 2030 ? Es wird lange Zeit gleichzeitige IPv4- und IPv6-Konnektivität geben müssen.
link IPv4 Netzwerk host node IPv4 Internet router node node node host host
link dual stack IPv6 Internet host IPv6 router node node IPv4 Internet node node host IPv4 router node node host host
link configured tunnel IPv6 Internet tunnel broker node host IPv6 router node node IPv4 Internet node node host IPv4 router node node IPv6-over-IPv4 tunnel host host
Windows XP 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 . . . . . . . . . : 141.89.224.1Tunnel 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:213cTunnel adapter Automatic Tunneling Pseudo-Interface: Connection-specific DNS Suffix . : IP Address. . . . . . . . . . . . : fe80::5efe:141.89.224.145%2 Default Gateway . . . . . . . . . :