The Next Generation Protocol IPv6 : The Next Generation Protocol Surasak Sanguanpong nguan@ku.ac.th http://www.cpe.ku.ac.th/~nguan Last updated: May 24, 1999

Agenda IPv4’s limitations Protocol Features Addressing IPv4 V.S. IPv6 functional comparison IPv4 to IPv6 migration Conclusion

IPv4’s limitations addressing : address depletion concerns Two driving factors : addressing and routing addressing : address depletion concerns IPv4 address space would exhaust between 2005 and 2011 [RFC1752] routing : routing table explosion currently ~50K entries in core routers more factors... opportunity to optimized on many years of deployment experience new features needed : multimedia, security, mobile, etc.. At some point in the near future the Internet will require a deployed new version of the Internet protocol. Two factors are driving this: routing and addressing. Global internet routing based on the on 32-bit addresses of IPv4 is becoming increasingly strained. IPv4 address do not provide enough flexibility to construct efficient hierarchies which can be aggregated. The deployment of Classless Inter- Domain Routing is extending the life time of IPv4 routing by a number of years, the effort to manage the routing will continue to increase. Even if the IPv4 routing can be scaled to support a full IPv4 Internet, the Internet will eventually run out of network numbers. There is no question that an IPng is needed, but only a question of when.

Key Issues support large global ๐ internetworks ๐ have a clear way to The new protocol MUST : ๐ support large global internetworks IPv4 IPv4 IPv4 IPv4 IPv4 IPv4 IPv4 IPv4 IPv4 IPv4 IPv4 IPv4 IPv4 IPv4 IPv4 IPv4 IPv4 IPv4 IPv4 IPv4 ๐ have a clear way to transition IPv4 based networks IPv4 There are several key issues that should be considered when reviewing the design of the next generation internet protocol. Some are very straightforward. For example the new protocol must be able to support large global internetworks. Others are less obvious. There must be a clear way to transition the current large installed base of IPv4 systems. It doesn't matter how good a new protocol is if there isn't a practical way to transition the current operational systems running IPv4 to the new protocol.

History of the IPv6 Effort (1) 1990 : IETF defined a new version of IP, generally later called IP Next Generation or IPng Spring 1992 : IAB proposed the OSI CLNP (Connectionless Network Protocol). Finally rejected by IETF and working groups

History of the IPv6 Effort (2) Feb 1992: 4 proposals for IPng CNAT, IP Encaps, Nimrod, Simple CLNP March 1992: evolving IP Encaps to IPAE (IP Address Encapsulation) Simple CLNP to TUBA (TCP and UDP with bigger Address) Dec 1992: 3 more proposals for IPng PIP (P Internet Protocol), SIP (Simple IP), and TP/IX Fall 1993 : resolution to 3 possibilities : TUBA TP/IX => CATNIP (Common Architecture for the Next Generation Internet Protocol) SIP+IPAE+PIP=> SIPP (Simple Internet Protocol Plus) Jul 1994 : SIPP was chosen, known as IPv6

IPv6 key advantages 128 bits fixed length IP address real time support self-configuration of workstations security features support mobile workstations protocol remains the same principle IPv4 compatibility

IPV6 address representation Hexadecimal values of the eight 16-bit pieces x:x:x:x:x:x:x:x Example FEDC:BA98:7654:3210:FEDC:BA98:7654:3210 1080:0:0:0:8:800:200C:417A Compressed form: "::" indicates multiple groups of 16-bits of zeros. 1080:0:0:0:8:800:200C:417A 1080::8:800:200C:417A FF01:0:0:0:0:0:0:101 FF01::101 0:0:0:0:0:0:0:1 ::1 0:0:0:0:0:0:0:0 :: ๐

IPV6 address representation, cont mixed environment of IPv4 and IPv6 address IPv4-compatible IPv6 address technique for hosts and routers to dynamically tunnel IPv6 packets over IPv4 routing infrastructure 0:0:0:0:0:0:13.1.68.3 => ::13.1.68.3 IPv4-mapped IPv6 address represent the addresses of IPv4-only nodes (those that do not support IPv6) as IPv6 addresses 0:0:0:0:0:FFFF:129.144.52.38 => ::FFFF:129.144.52.38

Format Prefix IPv6-address/prefix-length leading bits indicate specific type of an IPv6 address variable-length field represented by the notation: IPv6-address/prefix-length Example : the 60-bit prefix 12AB00000000CD3 12AB:0000:0000:CD30:0000:0000:0000:0000/60 12AB::CD30:0:0:0:0/60 12AB:0:0:CD30::/60

Type of addresses Unicast: defines a single interface. Three type of addresses Unicast: defines a single interface. A packet sent to a unicast address is delivered to the interface identified by that address. Anycast: defines a set of interfaces A packet sent to an anycast address is delivered to one of the interfaces Multicast: defines a set of interfaces A packet sent to a multicast address is delivered to all interfaces identified by that address

IPV6 address allocation

Aggregatable Unicast Address Three level hierarchy: Public Topology : providers and exchanges who provide public Internet transit services (P1, P2, P3, P4, X1, X2, P5 and P6) Site Topology : does not provide public transit service to nodes outside of the site (S1, S2, S3, S4, S5 and S6) Interface Identifier: interfaces on links X1 P1 P2 P3 P4 x2 P5 P6 S1 S2 S3 S4 S5 S6 FP TLA ID RES NLA ID SLA ID Interface ID 3 13 8 24 16 64 bits Public Topology Site Topology Interface Identifier TLA = Top Level Aggregation RES = Reserved NLA = Next-Level Aggregation SLA = Site-Level Aggregation FP=Format Prefix= 001

Header comparison Removed (6) Changed: (3) Added: (2) Expanded IPv4 ID, Flags, frag offset TOS, hlen header checksum Changed: (3) total length=> payload protocol => next header TTL=> hop limit Added: (2) traffic class flow label Expanded address 32 bits to 128 bits 0 15 16 31 vers hlen TOS total length identification flags frag offset TTL protocol header checksum source address destination address options and padding 20 bytes IPv4 vers traffic class flow label pay load length next header hop limit source address destination address 40 bytes IPv6

Autoconfiguration “Plug and play” feature Stateless mode : via ICMP (no server required) Prefix 4c00::/80 Link Address 00:A0:C9:1E:A5:B6 IPv6 Address 4c00::00:A0:C9:1E:A5:B6 + = Router adv. Stateful server mode : via DHCP DHCP request 00:A0:C9:1E:A5:B6 DHCP server DHCP response 4c00::00:A0:C9:1E:A5:B6

Multimedia support Flow1 Flow2 Applications reserve resources in advance via Flow Label Workstation Flow1 File Server PC Multimedia Server Flow2 All packets belonging to the same flow must be sent with the same source/destination address, traffic class, and flow label

Security Authentication/Confidential Authentication: MD5 based payload encryption Cipher Block Chaining mode of the Data Encryption Standard (DES-CBC)

Support Protocols ICMPv6 [RFC1885] DHCPv6 DNS extensions to support IPv6 [RFC1886] Routing Protocols RIPv6 [RFC2080] OSPFv6 IDRP IS-IS Cisco EIGRP

Transition Strategy Dual Stack run both IPv4 and IPv6 Tunneling IPv6 packet over IPv4 infrastructure Header Translation IPv4-only by header translation

Dual Stack Dual stack hosts support both IPv4 and IPv6 Determine stack via DNS Application TCP IPv6 IPv4 Ethernet IPV6 Dual stack host IPv4

Tunneling: automatic tunneling Encapsulate IPv6 packet in IPv4 rely on IPv4-compatible IPv6 address IPv6 host IPv4 Network IPv4/6 host ::1.2.3.4 2.3.4.5 R1 R2 ::2.3.4.5 2.3.4.5 2.3.4.5 6 traffic flow label payload len next hops src = ::1.2.3.4 (IPv4-compatible IPv6 adr) dst = ::2.3.4.5 payload 4 hl TOS len frag id frag ofs TTL prot checksum src: 1.2.3.4 dst: 2.3.4.5 6 traffic flow label payload len next hops src = ::1.2.3.4 (IPv4-compatible IPv6 adr) dst = ::2.3.4.5 payload 4 hl TOS len frag id frag ofs TTL prot checksum src: 1.2.3.4 dst: 2.3.4.5 6 traffic flow label payload len next hops src = ::1.2.3.4 (IPv4-compatible IPv6 adr) dest = ::2.3.4.5 payload

Tunneling : configured tunneling IPv6 host IPv6 host IPv4 Network 2000::A:A:B:C:D 2000::B:B:C:D:E IPv6 address (IPv4-compatible address are unavailable) R1 R2 ::2000:B:B:C:D:E R2 ::2000:B:B:C:D:E 6 traffic flow label payload len next hops src = 2000:A:A:B:C:D (IPv6 adr) dst = 2000:B:B:C:D:E (IPv6 adr) payload 4 hl TOS len frag id frag ofs TTL prot checksum src = R1 dst =R2 6 traffic flow label payload len next hops src = 2000:A:A:B:C:D (IPv6 adr) dst = 2000:B:B:C:D:E (IPv6 adr) payload 6 traffic flow label payload len next hops src = 2000:A:A:B:C:D (IPv6 adr) dst = 2000:B:B:C:D:E (IPv6 adr) payload Encapsulate IPv6 packet in IPv4 rely on IPv6-only address

Header Translation Full IPv6 system need to support fewIPv4-only systems rely on IPv4-mapped IPv6 address IPv6 host IPv4 host IPv6 Network ::FFFF:1.2.3.4 2.3.4.5 R1 R2 ::FFFF:2.3.4.5 ::FFFF:2.3.4.5 2.3.4.5 6 traffic flow label payload len next hops src = ::FFFF:1.2.3.4 (IPv4-mapped IPv6 adr) dst = ::FFFF:2.3.4.5 payload 6 traffic flow label payload len next hops src = ::FFFF:1.2.3.4 (IPv4-mapped IPv6 adr) dst = ::FFFF:2.3.4.5 payload 4 hl TOS len frag id frag ofs TTL prot checksum src = 1.2.3.4 dst = 2.3.4.5 payload

Migration Steps (1) upgrade DNS servers to handle IPv6 Address (2) Introduce dual stack systems that support IPv4 and IPv6 (3) Rely on tunnels to connect IPv6 networks separated by IPv4 networks (4) remove support for IPv4 (5) rely on header translation for IPv4-only systems

Conclusion IPv6 will provide for future Internet growth and enhancement IPv6 : solve the Internet scaling problem support large hierarchical address provide a flexible transition mechanism interoperate with IPv4 provide a platform for new Internet functionality

More Information Books WWW IPng: Internet Protocol next Generation, S. Bradner and A. Mankin, Addison-Wesley, 1996. IPng and the TCP/IP Protocols, Stephen A. Thomas, John Wiley & Sons, 1996. IPv6 : The New Internet Protocol, Christian Huitema, Prentice Hall,1996. WWW http://playground.sun.com/pub/ipng/html/ipng-main.html http://www.ietf.org/ids.by.wg/ipngwg.html http://www.ipv6.com