© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Introduction to IPv6 Evaluating IPv6 Features and Benefits

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v IPv6 Main Features Larger address space: –Global reach capability, flexibility, aggregation, multihoming, autoconfiguration, plug-and-play, renumbering Simpler header: –Streamlining of routing code Security and mobility Transition richness

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Larger Address Space IPv4 32 bits = 4,294,967,296 possible addressable nodes IPv6 128 bits: 4 times larger in bits = ~3.4 * possible addressable nodes = 340,282,366,920,938,463,463,374,607,431,768,211,456 = ~53,730,194,312 * billion * billion addresses per person on the planet IPv4 = 32 bits IPv6 = 128 bits

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Global Reachability Larger address space: A globally reachable address for everything End-to-end reachability, full support of application protocols, end-to-end security IPv6 Internet

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Multiple Levels of Addressing Hierarchy Larger address space: Multiple levels of hierarchy inside the address space More flexibility, new functionalities IPv6 = 128 bits

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Aggregation Larger address space: Aggregation of prefixes announced in global routing table Efficient and scalable routing Customer #2 2001:0410:0002::/ :0410:0001::/48 Only announces the /32 prefix 2001:410:1:1::/ :410:1:2::/64 Customer #1 ISP 2001:0410::/32 IPv6 Internet 2000::/3

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Multiple Addresses Larger address space: Multiple simultaneous addresses for hosts and networks Support of multihoming 2001:0410:0002:/ :0418:0001:/48 ISP 2001:0410::/32 Customer #2 ISP 2001:0418::/32 IPv6 Internet 2000::/3 Only announces its /32 prefix

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Stateless Autoconfiguration Larger address space: Often uses Layer 2 identifier Autoconfiguration with no collisions Plug-and-play Router sends network-type information (prefix, default route, etc.) Host autoconfigured address: prefix received + 64-bit Interface ID MAC address: 00:2c:04:00:fe:56

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Stateful Autoconfiguration Router announcement can indicate to hosts whether or not additional configuration parameters are available via stateful configuration (DHCPv6). Router sends network-type information and optionally sets DHCP available flag. Host receives router announcement that includes indication of whether to do stateless or stateful configuration. MAC address: 00:2c:04:00:fe:56

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Renumbering Larger address space: Renumbering, using autoconfiguration and multiple addresses Router sends NEW network-type information (prefix, default route, etc.) Host autoconfigured address: NEW prefix received + SAME link-layer address MAC address: 00:2c:04:00:fe:56

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Multicast Use Broadcasts in IPv4 –Interrupt all computers on the LAN, even if the destination is only one or two computers –Can completely bring down a network (broadcast storm) No broadcast in IPv6 –Replaced by scoped multicast Multicast –Enables efficient use of the network –Has much larger address range

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Simple and Efficient Header Simpler and more efficient header: 64-bit aligned fields and fewer fields Hardware-based efficient processing Improved routing efficiency, performance, and forwarding rate scalability IPv4 HeaderIPv6 Header

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v No Checksum Simpler and more efficient header: No checksum at the IP layer, no recalculation by the routers Improved routing efficiency, performance, and forwarding-rate scalability Error detection done by link layer and transport layer IPv6 Header checksum

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Simpler and more efficient header: A new flow label inside IP header Enables per-flow processing for differentiation at the IP layer Length of 20 bits IPv6 Header Flow Label Flow Label Field Enables Per-Flow Processing

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Extension Headers Simpler and more efficient header: Flexible extension headers More efficient handling of IP options Faster forwarding rate and end-node processing IPv6 Basic Header Any Number of Extension Headers Data (for example, TCP or UDP) IPv6 Packet

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v TCP Header + Data IPv6 Header Next Header = Routing Routing Header Next Header = TCP TCP Header + Data IPv6 Header Next Header = TCP IPv6 Header Next Header = Routing Routing Header Next Header = Destination Destination Header Next Header = TCP TCP Header + Data Extension Headers (Cont.) Extension headers are daisy-chained

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Mobility Mobility: Mobile devices are fully supported while moving. Mobility is built-in with IPv6. –Any node can use it. Efficient routing means performance for end users. IPv6 Internet

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v IPv6 Internet Security Security: End-to-end network security (integrity, authentication, confidentiality) Inherent (built-in) with IPv6 –Usable by any node

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Transition Richness Transition richness: No fixed day to convert, no need to convert all at once Different transition mechanisms available –Smooth integration of IPv4 and IPv6 Different compatibility mechanisms –Communication between IPv4 and IPv6 nodes IPv6 Traffic IPv6 Host 6to4 Router IPv6 Network IPv4 Network IPv6 Host IPv6 Network 6to4 Router

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Quality of Service: Not a New Feature QoS QoS has been mentioned as an IPv6 featurein fact IPv6 currently does QoS the same way as IPv4. IPv6 uses Traffic Class field in same manner as IPv4. There is no difference between QoS protocols and methods in IPv4 and IPv6. The IPv6 flow label can be used for QoS devices to identify specific flows. The flow label itself is not currently specified as a QoS feature.

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v IPv6 Technology Scope IP ServiceIPv4 SolutionIPv6 Solution Addressing Range 32-bit, Network Address Translation 128-bit, multiple scopes AutoconfigurationDHCP Stateless, Stateful (DHCPv6) SecurityIPsec IPsec-mandated, works end-to-end MobilityMobile IP Mobile IP with optimized routing Quality of Service differentiated service, integrated service IP MulticastIGMP/PIM/Multicast BGP MLD/PIM/multicast BGP, scope identifier

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Summary IPv6 has many compelling features and real benefits over IPv4 in supporting global networks effectively. A number of feature enhancements, such as the way IPv6 performs autoconfiguration or aggregates routing information make IPv6 attractive. The large address space is one IPv6 benefit. With the 128-bit address space of IPv6, rather than the 32-bit address space of IPv4, the number of devices that can be connected to the network increases many fold. The large address space for IPv6 supports autoconfiguration by reserving 64bits for the host number on a given subnet. The large and standardized address space allows routers to send configuration information to hosts, enabling routers to configure their own global-scope address. With such a large addressing space, strict route aggregation is critical to avoid explosion in the size of the default-free routing tables on the global Internet backbone.

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v