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IPv6 Defined

IPv6 Defined. Internet Protocol version 6 Originally known as IPng, or IP Next Generation Network Layer protocol for packet switched networks Successor of IPv4 which supports about 4.3 billion addresses (2 32 addresses) IPv6 increased the number of addresses to (2 128 addresses)

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IPv6 Defined

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  1. IPv6 Defined • Internet Protocol version 6 • Originally known as IPng, or IP Next Generation • Network Layer protocol for packet switched networks • Successor of IPv4 which supports about 4.3 billion addresses (232 addresses) • IPv6 increased the number of addresses to (2128 addresses) • Useful for mobility, QoS, and privacy extension

  2. WOW! 2128 Addresses • 340,282,366,920,938,000,000,000,000,000,000,000,000 • 340*1036 • million, billion, trillion, what?.... • NO!! It’s 340 undecillion in America • or • 340 sextillion in Europe

  3. Picture This! • 430 quintillion addresses per sq. inch of the Earth’s Surface • Quintillion = American term for 1018 • Trillion = European term for 1018 • That’s more than a trillion addresses per square centimeter of surface on the planet • Each person on Earth could be assigned 7 unique addresses for every atom in his or her body!(assuming 1,027 atoms per human for roughly 6.5 billion people alive today) • 252 for every star in the known universe!

  4. Questions to ponder? • Do we really need this extremely large address space? • Is this overkill? • How will this effect our networks, servers hosts etc.? • What about overhead on equipment and on our bandwidth? • What happened to IPv5? Did we skip a version?

  5. Examine the Facts • IPv6 longer address length is needed for: • Routing Aggregation • Autoconfiguration of Addresses • Improved scalability for multicast routing • More efficient forwarding • Greater flexibility to introduce new options • Flow labeling to aide in QoS and special handling

  6. Benefits • Easier allocation of address blocks • Flexibility of ISPs to subdivide blocks for customers • Organizations can subdivide blocks for internal networks • Unique IP addresses facilitate End-To-End (E2E) connections • Embedded Quality of Service (QoS) to support services like VoIP & IP Video

  7. Okay, so what happened to IPv5? • IPv5 was NOT a successor to IPv6 • Known as Internet ST (Stream Protocol) • Intended to be a connection oriented complement to IPv4 • Experimental protocol….Not in public use

  8. IPv4 vs IPv6 • IPv4 • Fewer total addresses • Address depletion • Scalability problems • Exponential growth of Internet & number of routes • Need private addressing and Network Address Translation (NAT) • Provides IP for ISPs, companies, governments, and educational institutions • Represented in dotted decimal notation • IPv6 • Does not need NAT • More addresses with additional levels of hierarchy to support network growth • Increased bandwidth overhead • Requires DNS • Difficult to memorize addresses • Provides IP for ALL citizens! • NO BROADCASTS! • Represented in Colon Hexadecimal notation • Backward compatible with IPv4

  9. Improvements Larger address space – 128bit verses 32 bit Autoconfiguration with or without DHCP: without DHCP called stateless autoconfiguration Fewer fields in header/no checksum/fixed lengt5h IP mobility and Security ARP broadcast replaced with multicast request

  10. What’s driving the need?? • Internet growth • Mobile devices • PDAs • Mobile phones • Tablet PCs • Gaming • Voice/Video • Security Monitoring • Appliances • Medical Imaging • Animal Tags • Media Services • Traffic Control • Planes • Automobiles • Hotspots

  11. IPv6 Addressing Format • Written in Colon Hexadecimal Notation • Typically see the IPv6 Address followed by a slash “/” for the Prefix Length • Prefix Length is the number of leftmost bits that represent the prefix, written in slash notation just like CIDR in IPv4 • IPv6 Ex: 2001:c001:c15c::/48 • Two colons “::” represent successive leading zeroes • Example: 2001:0:0:0:260:97FF:FE02:6EA5 same as 2001::260:97FF:FE02:6EA5

  12. AutoconfigurationStateless Autoconfiguration • AIPRA has a problem of not finding gateway when no DHCP server available: local LAN communication only • Stateless the client not only gives it’s self the IP address but also “asks” via a multicast,if there is a router/gateway and assigns that address • Example of address would be: • FF01:0:0:0:0:0:2 used to multicast to all routers for node-local)

  13. IPv6 Header FieldsFixed length of 40 Bytes Version – version 6 (4 bits) Traffic Class – packet priority (8 bits) where source provides congestion or non-congestion control Flow Label – QoS management (20 bits) Payload Length – when set to zero, the option is “jumbo payload” or hop-by-hop which carries optional info that must be examined by every node (16 bits) Next Header – next encapsulated protocol compatible with IPv4 protocol field. (8 bits) Hop Limit – replaces the TTL (time to live) in IPv4 (8 bits) Source Address and Destination Address – (128 bits each)

  14. Mobility and Security Layer 3 only TCP and UDP are still being used No need for IPsec

  15. Going from 4-6:Dual-Stack • Devices are IPv6 Aware • Devices speak both IPv6 and IPv4 • Dual Stack is the primary approach for introducing IPv6 into an IPv4 network • Not working: even if using internally, externally not using • Bullet list page 71

  16. IPV6 Book example 2001:0DB8:000:0000:1234:0000:A9FE:133E • In DNS A for ver4 alias: AAAA for ver6 :0: stands for :0000 compress 0 So: 2001:0DB8:000:0000:1234:0:A9FE:133E You can omit preceding 0 in any 16bit work So: 2001:DB8:000:0000:1234:0:A9FE:133E :: used to represent 0 to round out address to 128 – can only be used once 2001:DB8::1234:0:A9FE:133E Can also use / Network address is 32bits: 2001::DBB:0000:0000:0000:0000:0000:0000 Wrote as: 2001:DBB:: /32

  17. Assignment 32 bit network portion: 96 bits for you to work with You can subnet, but don’t need to: ISP would normally give you a portion of the 96 bits No vlsm etc. Can have DHCP or not

  18. IPv6 Addresses • Unicast – identifies a single interface on a single node. A unicast packet is delivered to the identified single interface. • Multicast - identifies a set of interfaces that belong to different nodes. A multicast packet is delivered to all identified interfaces. • Anycast – a global unicast address that is assigned to a set of interfaces that belong to different nodes. An anycast packet is delivered to the closest interface. • Broadcast – Not in IPv6!!!

  19. IPv6 Special Addresses • Reserved – reserved by IETF for special uses. First eight bits are 00000000. IPv4 embedded addresses use this block. • Private – local link – private addresses are local to a particular site or company network and are never routed outside that network. First nine bits are: 111111101 • Loopback – used for testing the “loop back” of the device. 0:0:0:0:0:0:0:1/128 or ::1/128 • Unspecified – used in the source field when a host is seeking to have its IP address configured. All 128 bits are zeroes noted as 0:0:0:0:0:0:0:0, ::, or 0::0. • Page 76 describes more

  20. IPv6 Unicast Addresses • 64 bits for Subnet + 64 bits for Interface ID • Prefix + Subnet ID + Interface ID = IPv6 128 bit Address • Prefix is the Global Routing Prefix (48 bits) • Subnet ID is the subnet identifier within a site (16 bits) • Interface ID is the interface identifier for a particular host or other device (64 bits) • Represented in 16 bit Hexadecimal Number From ONE: To ONE: SOURCE -----------------------------Unicast Destination

  21. Routing Prefix • Like the Network ID in IPv4 • 48 bits • 1st three bits are fixed at “001” for unicast • Next 45 bits - Regional Internet Registries determine how these bits are allocated. • These bits are typically a combination of Level Identifier fields. • For example, you could have: Level 1 Identifer (10 bits) for largest organizations + Level 2 Identifer (12 bits) for lower level organizations + Level 3 Identifer (23 bits) for Level 2’s customers

  22. Who’s in charge? • IANA – Internet Assigned Numbers Authority is in charge of all IP address assignment and internet parameters. (owned and ran by ICANN) • ICANN – Internet Corporation for Assigned Names and Numbers is a private, non-profit company responsible for all registration tasks such as IP address assignment, domain name assignment, and protocol parameters management. (ICANN has allowed accredited registrars to register names in many of the top-level domains) Often referred to as: IANA/ICANN or ICANN/IANA

  23. What’s an RIR? Back to IPv6 Addresses…How do they do it? • IANA assigns largest blocks of addresses to RIRs (Regional Internet Registries) • An RIR is a Regional Internet Registry that is responsible for managing IP addresses and Autonomous System numbers for a particular region.

  24. So who are the RIRs? • APNIC – Asia Pacific Network Information Centre responsible for Asia/Pacific region • ARIN – American Registry for Internet Numbers responsible for North America, part of the Carribean • LACNIC – Latin American and Carribean Internet Addresses Registry responsible for Latin America and part of the Carribean • RIPE-NCC – Réseaux IP Européens Network Coordination Center responsible for Europe, Middle East, and Central Asia • AfriNIC - African Internet Numbers Registry responsible for continental Africa and the Indian Ocean

  25. Multicast Scopes • Node-Local (within a node) • Link-Local (within a local network) • Site-Local (within a local site) • Organization-Local (within an organization) • Global (across the Internet) Note: As the Scope ID Value Increases, the Scope expands to cover larger areas.

  26. Well Known Multicast Addresses • FF01:0:0:0:0:0:1 used to multicast to all nodes for node-local. (Notice: FF signifies multicast, scope id of 1 signifies node-local, and group id of 1 signifies all nodes) • FF02:0:0:0:0:0:1 used to multicast to all nodes for link-local. (Notice: FF signifies multicast, scope id of 2 signifies link-local, and group id of 1 signifies all nodes) Multicasting to “all nodes” replaces IPv4 Broadcasts.

  27. More well-known Multicast Addresses • FF01:0:0:0:0:0:2 used to multicast to all routers for node-local. (Notice: FF signifies multicast, scope id of 1 signifies node-local, and group id of 2 signifies all routers) • FF02:0:0:0:0:0:2 used to multicast to all routers for link-local. (Notice: FF signifies multicast, scope id of 2 signifies link-local, and group id of 2 signifies all routers) • FF05:0:0:0:0:0:2 used to multicast to all routers for node-local. (Notice: FF signifies multicast, scope id of 5 signifies site-local, and group id of 2 signifies all routers)

  28. IPv6 Anycast Addresses • Anycast Packets are new to IPv6 • Automatically sends packet to the closest member within a group. • Provides flexibility when requesting a service provided by several different routers. • Designed for devices within the same network. • Addresses assigned from Unicast Addressing space. • Subnet Prefix (# bits) + Interface Identifier (128 - # bits in Subnet Prefix) = IPv6 128 bit Anycast Address • Interface Identifier is set to ALL 0’s. • Subnet-Router Anycast Address is required to communicate with one of multiple routers in a particular subnet. From ONE: To ONE of Many: SOURCE ------------------------------- Multicast Destination ------------------------------- Multicast Destination ----------------------------- CLOSEST Multicast Destination

  29. Deploying IPv6 • Migration to IPv6 from IPv4 will not occur all at once…it’s way too complex • IPv4 and IPv6 must coexist • Migration requires careful planning • Overall transition worldwide will take several years

  30. Migrating from IPv4 to IPv6 • Methods that make the migration easier. • Dual-Stack – running both IPv4 and IPv6 simultaneously. Applications talk to both. • Tunneling – wrapping or packaging one type of packet into another to be sent on dissimilar network i.e., tunneling ipV6 packets on IPv4 network • Translation – converting IPv4 to IPv6 and vice versa which can be complex and result in problems. Required for devices that only support one version. (temporary solution until more devices make the move to IPv6) • IPv6/IPv4 Address Embedding – embeds the IPv4 addresses within the IPv6 address structure

  31. Tunneling • Enables interconnection of IP networks. • IPv6 networks can be connected through an IPv4 WAN link. • IPv6 packets are encapsulated and decapsulated by border routers for transmission over the IPv4 WAN link. • Thus, IPv6 packets are tunnelled through the IPv4 network cloud.

  32. Translation • Required when IPv6 host needs to communicate with IPv4 host. • Application Level Gateways (ALGs) are required to translate. • Can be implemented in border routers and hosts. • Temporary Solution • Complexity and overhead issues

  33. IPv6/IPv4 Address Embedding • Addresses are in the Reserved Block for IPv6 addresses. • The first 80 bits are zeroes. (Recall that the reserved block has zeroes in the first 8 bits) • IPv4 addresses are put in special format IPv6 address so they are recognized as IPv4 addresses by IPv6 devices.

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