Transitioning to IPv6 April 15,2005 Presented By: Richard Moore PBS Enterprise Technology

Agenda >Benefits of IPv6 >What is IPv6? >IPv6 Operation >IPv6 Deployment >IPv6 Challenges >Resources

Improved Routing Efficiency >IPv6’s large addressing space >Multi-level address hierarchy >Reduces the size of Internet routing tables >All fields in the IPv6 header are 64 bit aligned

Supports Autoconfiguration >Accommodates mobile services >Accommodates Internet capable appliances >Decreases complexity of network discovery >Simplifies renumbering of existing networks >Simplifies transition between networks

Embedded IPsec >IPsec is a mandatory part of IPv6 protocol >Protocol provides security extension headers >Eases implementation of encryption, authentication, and VPN >Provides end-to-end security

Support for Mobile IP and Mobile Computing Devices >Allows mobile devices to move without breaking existing connections >Care-of-Address eliminates need for foreign agents >Simplifies communication of Corresponding nodes directly with Mobile nodes

Elimination of Network Address Translation (NAT) >NAT is a mechanism to share or reuse the same address space among different network segments >NAT places a burden on network devices and applications to deal with address translation

Supports Widely Deployed Routing Protocols >Extended support for existing Interior Gateway Protocols and Exterior Gateway Protocols >For example: OSPFv3, IS-ISv6, RIPng, MBGPv4+

Improved Support for Multicast >Replaces IPv4 broadcast functionality >Improves network efficiency

IPv6 Header Format >IPv6 header is streamlined for efficiency >Greater flexibility to support optional features

IPv6 Extension Headers >Extension header is optional >64 bit aligned, lower overhead >No size limit as with IPv4 >Processing only by destination node. >Next header field identifies the extension header

IPv6 Addressing >128-bit address is separated into eight 16-bit hexadecimal numbers >For example: 2013:0000:1F1F:0000:0000:0100:11A0:ADFF

IPv6 Addressing >Conventions are used to represent IPv6 addresses >Leading zeros can be removed, 0000 = 0 (compressed form) >“::” represents one or + groups of 16 bits zeros >For example: 2001:0:13FF:09FF:0:0:0:0001 = 2001:0:13FF:09FF::1

IPv6 Addressing >Lower four 8 bits can use decimal representation of IPv4 addresses >For example: 0:0:0:0:0:0: >IPv6 node allows more than one type of IP address

Unicast & Global Unicast Addressing >Unicast: An address used to identify a single interface >Global Unicast: An address that can be reached and identified globally

Site-local Unicast Addressing >An address that can only be reached and identified within a customer site >Similar to IPv4 private address

Link-local Unicast Addressing >An address that can only be reached and identified by nodes attached to the same local link.

Anycast Addressing >A global address that is assigned to a set of interfaces belonging to different nodes >Must not be used as source address of IPv6 packet >Must not be assigned to an IPv6 host

Multicast Addressing >Address assigned to a set of interfaces belonging to different nodes

Neighbor Discovery >Determines link-layer address of neighbor on the same network >Determines the link-layer address of another node on the same local link >Advertisement messages are also sent when there are changes in link-layer addressing of a node on a local link

Router Discovery >Discovers routers on local link using advertisements and solicitation messages >Determines type of autoconfiguration a node should use >Determines Hop limit value >Determines network prefix >Determines lifetime information >Determines default router

Stateless Autoconfiguration and Renumbering of IPv6 Nodes >Stateless autoconfiguration uses network prefix information in router advertisement messages >Remaining 64 bits address is obtained by the MAC address assigned to the Ethernet interface combined with additional bits in EUI-64 format >Renumbering of IPv6 nodes is possible through router advertisement messages containing old and new prefix

Path Maximum Transfer Unit (MTU) >IPv6 routers do not handle fragmentation of packets >Uses ICMP error reports to determine packet size matching MTU size >Allows a node to dynamically discover and adjust differences in MTU size

DHCPv6 and DNS >Supports stateful configuration with DHCPv6 >Node has option to solicit an address via DHCP server when a router is not found >DHCPv6 is similar to DHCPv4 >DHCPv6 uses multicast for messaging >New record type to accommodate IPv6 addressing in DNS

Dual-stack Backbone >All routers maintain both IPv4 and IPv6 protocol stacks >Applications choose between using IPv4 or IPv6 >All routers in the network must be upgraded to IPv6 >All routers must have sufficient memory for both IPv4 and IPv6 routing tables

IPv6 over IPv4 Tunneling >Encapsulates IPv6 traffic within IPv4 packets

Manually Configured Tunnels >Defined by RFC 2893, both end points of tunnel must be configured with appropriate IPv6 and IPv4 addresses >Edge routers will forward tunneled traffic based on the configuration

GRE Tunnels >GRE allows one network protocol to be transmitted over another network protocol >Packets are encapsulated to be transmitted within GRE packets >GRE is an ideal mechanism to tunnel IPv6 traffic

IPv4 Compatible Tunnels >Defined in RFC 2893, tunnel mechanisms automatically set up tunnels based on IPv4-compatible IPv6 addresses >IPv4-compatible IPv6 address defines the left-most 96 bits as zero, followed by an IPv4 address >For example: 0:0:0:0:0:0:

6to4 Tunnels >Defined by RFC 3056, 6to4 tunneling uses an IPv4 address embedded in the IPv6 address >Identifies the end point and configures tunnel automatically

ISATAP Tunnels >ISATAP tunneling is similar to 6to4 tunneling >Designed for use in a local site or campus network

Teredo Tunnels >Provides address assignment and host-to-host automatic tunneling for unicast IPv6 connectivity across the IPv4 Internet when IPv6/IPv4 hosts are located behind one or multiple IPv4 NATs. >To traverse IPv4 NATs, IPv6 packets are sent as IPv4- based User Datagram Protocol (UDP) messages.

MPLS Tunnels >Isolated IPv6 domains can communicate with each other over MPLS IPv4 core networks >MPLS forwarding is based on labels rather than IP headers requiring fewer infrastructure upgrades or reconfigurations >Allows IPv6 networks to be combined into VPNs or extranets over IPv4 VPN infrastructure

IPv6 Challenges

Resources >Questions or Comments?