Introduction to IPv6

Transcription

1 Introduction to IPv6 1

2 IP Next Generation - Agenda Rationale behind IPv6 IPv6 functionality Transition strategy IPv6 current status 2

3 Rationale Behind IPv6 Address depletion concerns? Circa 1994 routing table increases, ip address availability CIDR deployed, currently prefixes in the IPv4 Internet routing table Latest estimates - okay for another 5 to 10 years only 3

4 Rationale behind IPv6 Opportunity to optimise on many years of deployment experience Integrate autoconfiguration, security, real-time flow support, etc Protocol should remain the same, in principle 4

5 IPv6 Features/Functionality Expanded Address Space Autoconfiguration Realtime/Multimedia support Integrated Security Support IPv4 fi IPv6 transition strategy 5

6 IPv6 - so what s really changed? IPv4 Header: Version IHL Type of Service Total Length Identification Flags Fragment Offset Time to Live Protocol Header Checksum IPv6 Header: Version Traffic Class Options Payload Length Source Address - 32 bits Destination Address - 32 bits Flow Label - 20 bits Next Header Source Address bits Destination Address bits Padding Hop Limit Address space quadrupled to 16 bytes Fixed Length (optional headers daisy chained) No checksumming (done by link layer) No hop by hop segmentation (path MTU discovery) Flow Label/Priority (integrated QoS support) 6

7 IPv6 Autoconfiguration Stateless host autonomously configures its own address Link local addressing Stateful DHCPv6 Addressing Lifetime Facilitates graceful renumbering SUBNET PREFIX Addresses defined as valid, deprecated or invalid SUBNET PREFIX + MAC ADDRESS SUBNET PREFIX + MAC ADDRESS (single subnet scope, formed from reserved prefix and link layer address) 7

8 IPv6 Real Time/Premium Services support Flow based, defines flow label and priority Can be combined with source routing header options Integration with MPLS Version Traffic Class Insertion into IPv6 Traffic Class Field Tag CoS (Reference/Draft RFC:- draft-baker-flow-label-00.txt) 8

9 IPv6 Security IPSec Architecture Export restrictions now relaxed Authentication MD5 based Confidentiality - DES encrypt entire datagram or IP payload Retain existing use of (packet filtering based) firewalls 9

10 IPv6 Transition Strategy Key to successful adoption and production deployment Goal - facilitate partial/incremental upgrades Hosts, Servers, DNS, Routers Two approaches hosts network 10

11 IPv6 Transition Strategy - Approaches Hosts - Dual Stack (IPv6 API defined) APPLICATION TCP/UDP IPv4 IPv6 DRIVER Networks - Tunnelling DATA Transport Layer Header IPv6 Header DATA Transport Layer Header IPv6 Header IPv4 Header More efficient than building new IPv6 topology 11

12 IPv6 Tunnelling Configured tunnels - manual point-2-point links Automatic tunnels - via IPv4 compatible IPv6 addresses (96 bits of zeros prefix - 0:0:0:0:0:0/96) Driver IPv4 IPv6 IPv6 IPv4 Driver IPv4 Backbone IPv6 IPv6 IPv6 Cisco instrumental in building existing 6Bone Network Address Translation IPv4 IPv6 12

13 IPv6 Routing Existing routing protocols extensions for IPv6 RIPv6 Same destination/mask/metric information as RIPv2 Multiprotocol BGP4+ Now standard Integrated IS-IS 20 byte NSAP support facilitates IPv6 address/routing EIGRPv6 Reflects Cisco s future proofing commitment OSPFv3 Packet formats changed to reflect 128 bits Neighbour Discovery - dynamic host router combination of ES-IS, ARP and ICMP Redirect 6bone is the IPv6 testbed join 6bone to trial IPv6, addressing, services, implementations, 13

14 IPv6 Addresses Aggregatable Global Unicast Format - RFC2374 Address hierarchy matches Internet Service Provider hierarchy FP TLA ID Reserved NLA ID SLA ID Interface ID 3 bits 13 bits 8 bits 24 bits 16 bits 64 bits Terminology: FP - Format Prefix: Unicast (001), Multicast, Anycast TLA - Top Level Aggregator fi Global ISP NLA - Next Level Aggregator fi ISP SLA - Site Level Aggregator fi Customer Interface ID - Host 14

15 IPv6 Addresses Minimum assignment to end-site or customer is a /48 prefix: 16 bits for subnetworks subnetworks per site 64 bits for hosts million hosts per subnetwork!! 15

16 IPv6 Addresses - 6bone Test address space defined in RFC2471-3FFE::/16 FP TLA ID ptla ID NLA ID SLA ID Interface ID 3 bits 13 bits 8 bits 24 bits 16 bits 64 bits Definitions: FP - Format Prefix 001 TLA - special TLA 0x1FFE ptla - pseudo Top Level Aggregator fi Transit ISP Guidelines for routing on 6bone - RFC

17 IPv6 Addresses Bootstrap process - RFC2450 FP TLA ID subtla ID NLA ID SLA ID Interface ID 3 bits 13 bits 13 bits 19 bits 16 bits 64 bits Definitions: TLA - special TLA 0x0001 subtla - Top Level Aggregator fi Transit ISP NLA - Next Level Aggregator fi ISP SLA - Site Level Aggregator fi Customer Interface ID - Host 17

18 IPv6 Addresses Where to get address space? Real IPv6 address space now allocated by APNIC, ARIN and RIPE NCC APNIC 2001:0200::/23 ARIN 2001:0400::/23 RIPE NCC 2001:0600::/23 Go to your existing IPv4 address registry... 18

19 IPv6 Address Space Current Allocations APNIC (whois.apnic.net) RIPE (whois.ripe.net) WIDE-JP :200::/35 EU-UUNET :600::/35 NUS-SG :208::/35 DE-SPACE :608::/35 CONNECT-AU :210::/35 NL-SURFNET :610::/35 NTT-JP :218::/35 UK-BT :618::/35 KIX-KR :220::/35 CH-SWITCH :620::/35 JENS-JP :228::/35 AT-ACONET :628::/35 ETRI-KRNIC-KR :230::/35 UK-JANET :630::/35 HINET-TW :238::/35 DE-DFN :638::/35 ARIN (whois.arin.net) ESNET-V6 2001:400::/35 VBNS-IPV6 2001:408::/35 RU-FREENET :640::/35 GR-GRNET :648::/35 DE-ECRC :650::/35 This output current as of 19-Feb

20 IPv6 Addresses Bootstrap phase Minimum assignment to ISP is a /35 ISP creates own NLA boundary - or - ISP assigns /48 SLAs to each customer 16 bits for subnetworks subnetworks per site 64 bits for hosts million hosts per subnetwork!! 20

21 IPv6 Addresses Bootstrap phase subtla holder ISP allocates SLAs to endcustomers ISP addresses site addresses ISP allocated subtla NLA ID SLA ID Interface ID 35 bits 13 bits 16 bits 64 bits subtla holder ISP creates its own NLA boundary for customer ISPs ISP addr ISP2 addr site addresses ISP allocated subtla NLA1 NLA2 SLA ID Interface ID 35 bits 6 bits 7 bits 16 bits 64 bits 21

22 IPv6 Current Status - Standardisation Several key components now on Standards Track: Specification (RFC2460) Neighbour Discovery (RFC2461) ICMPv6 (RFC2463) IPv6 Addresses (RFC2373/4/5) RIP (RFC2080) BGP (RFC2545) IGMPv6 (RFC2710) OSPF (RFC2740) Router Alert (RFC2711) Jumbograms (RFC2675) Autoconfiguration (RFC2462) IPv6 over: PPP (RFC2023) Ethernet (RFC2464) FDDI (RFC2467) Token Ring (RFC2470) NBMA(RFC2491) Frame Relay (RFC2590) ATM (RFC2492) ARCnet (RFC2549) 22

23 IPv6 Current Status - Work in Progress to Standardisation Issues remaining open Multihoming Ongoing work at the moment Extension Headers? ISIS draft-ietf-isis-ipv6-00.txt DHCPv6 draft-ietf-dhc-dhcpv6-14.txt 23

24 Barriers IPv6 Current Status - Adoption/Deployment compelling business reasons + potential cost application availability Drivers IPv6 address availability (less IPv4) proactive policy + forward planning consolidation + customer demand draft-ietf-ngtrans-introduction-to-ipv6-transition-02.txt draft-ietf-iab-case-for-ipv6-05.txt 24

25 IPv6 Current Status - Customers/Vendors Cisco customer base requesting IPv6 support Service Providers Enterprise Academic Community Vendor support Cisco Microsoft Apple Kame FTP Software Bay 3com Hitachi IBM Trumpet Software Telebit Compaq Linux Sun many more 25

26 Cisco IPv6 IOS Beta test images are available! On CCO - account required Platform range: most routers from 800 to GSR! Based on recent 12.0T software Process switching only 26

27 Cisco IPv6 IOS First release images available mid 2000 with 12.1(5)T IOS release Support 27

28 Conclusion IPv6 in production deployment Further Reading

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