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1. Transitioning to IPv6 April 15,2005
Presented By:
Richard Moore
PBS Enterprise Technology
2. Agenda
Benefits of IPv6
What is IPv6?
IPv6 Operation
IPv6 Deployment
IPv6 Challenges
Resources
3. 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
4. Supports Autoconfiguration
Accommodates mobile services
Accommodates Internet capable appliances
Decreases complexity of network discovery
Simplifies renumbering of existing networks
Simplifies transition between networks
5. 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
6. 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
7. 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
8. Supports Widely Deployed Routing Protocols
Extended support for existing Interior Gateway Protocols and Exterior Gateway Protocols
For example:
OSPFv3, IS-ISv6, RIPng, MBGPv4+
9. Improved Support for Multicast Replaces IPv4 broadcast functionality
Improves network efficiency
10. IPv6 Header Format IPv6 header is streamlined for efficiency
Greater flexibility to support optional features
11. 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
12. IPv6 Addressing
128-bit address is separated into eight 16-bit hexadecimal numbers
For example:
2013:0000:1F1F:0000:0000:0100:11A0:ADFF
13. 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
14. IPv6 Addressing
Lower four 8 bits can use decimal representation of IPv4 addresses
For example:
0:0:0:0:0:0:192.168.0.1
IPv6 node allows more than one type of IP address
15. Unicast & Global Unicast Addressing
Unicast: An address used to identify a single interface
Global Unicast: An address that can be reached and identified globally
16. Site-local Unicast Addressing
An address that can only be reached and identified within a customer site
Similar to IPv4 private address
17. Link-local Unicast Addressing
An address that can only be reached and identified by nodes attached to the same local link.
18. 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
19. Multicast Addressing
Address assigned to a set of interfaces belonging to different nodes
20. 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
21. 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
22. 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
23. 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
24. 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
25. 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
26. IPv6 over IPv4 Tunneling
Encapsulates IPv6 traffic within IPv4 packets
27. 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
28. 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
29. 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:
0:0:0:0:0:0:64.29.51.26
30. 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
31. ISATAP Tunnels
ISATAP tunneling is similar to 6to4 tunneling
Designed for use in a local site or campus network
32. 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.
33. 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
34. IPv6 Challenges
35. Resources
Questions or Comments?
rmoore@pbs.org