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CS4550 Computer Networks II IP Version 6. Why IPv6? (1) IPv6 Challenges (1) IPv6 Addressing and Packet Format (3) IPv6 Routing (2) IPv6 Other Topics (1) IPv6 Related Standards (1) Transitioning to IPv6 (1) IPv6 Current Status. IP topics. Why IPv6?.
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Why IPv6? (1) IPv6 Challenges (1) IPv6 Addressing and Packet Format (3) IPv6 Routing (2) IPv6 Other Topics (1) IPv6 Related Standards (1) Transitioning to IPv6 (1) IPv6 Current Status IP topics
Why IPv6? • IPv4 Proposed in 1975, adopted 1981 • Served well, but 24 years old! • Address Depletion • Explosion in growth of routing tables • non-hierarchical in nature • Routing Performance • Packets “costly” to analyze enroute • Security Issues - no organic support • New technologies • telephony, video, e-commerce, etc • Piece of “the puzzle” to enable new services • Gigabit Ethernet, RSVP, IPv6, etc
IPv6 Challenges • Backwards Compatibility • MUST work with existing equipment • Perpetual co-existence with IPv4 • Co-exist with current standards/protocols • New v6 aware protocols to take advantage of v6 features • Reduce Latency & provide QOS!!! • Enable streaming data
IPv6 addressing • IPv4 Address Space • 232 = 4,294,967,296 -- but many wasted • CIDR has helped…BUT is a band aid approach • IP masquerading, proxies, NATs • IPv6 Address Space • 2128 = 3.4x 1038 addresses • 340,282,366,920,938,463,374,607,431,768,211,456 addresses • hierarchical….aggregatable (sic) • Address Notation: X:X:X:X:X:X:X:X • where X=16 bits • FEDC:BA98:7654:3210:FEDC:BA98:7654:3210 • 1080:0:0:0:8:800:2C:417C • 1080::8:800:2C:417C
64 bits..Divided by subscriber into Subnet and Interface ID (NOTE: this address space is 2x IPv4’s ENTIRE address space! Provider Based Unicast Address -- SUGGESTED FORMAT Subscriber ID 010 Provider ID Registry ID Intra-Subscriber 128 0 64 m n 3 16bit subnet ID 48-bit IEEE 802 MAC address IDs the registry that assigned the provider portion of the address IDs the provider that assigned the subscriber portion of the address IDs a particular subscriber 128 64 80 IPv6 addressing hierarchy • Continuously bit-wise maskable • may formats possible • fully customizable at each level • Format for auto configuration • Also supports aggregate routes Received from router during auto-config Host Provided
1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 Traffic Class Version Flow Label Payload Length (in octets) Hop Limit Next Header Type Source Address (x4 lines) Destination Address (x4 lines) IPv6 Packet Format • MUCH Simplified • Fixed Length - 40 bytes • Extension Headers • 8 Optional Headers Defined • Authentication Header (MD5) • MD5 • Encapsulating Security Payload • 56bit DES • HMAC w/MD5 or w/SHA-1 1 hop-by-hop (only one examined in route) 2 Fragment 3 destination options 4 routing 5 Authentication 6 Encryption
IPv6 Routing • Routers CANNOT Fragment • Fragmentation done at source host • guaranteed minimum 576 byte path • (93%) efficiency • Shorter & Simplified Headers • Faster Analysis • Most Optional Headers Ignored in Routing • Hierarchical Addressing • Smaller Routing Tables • Route aggregation similar to CIDR • Flow Control Labels • Flow Control Labeled packets are “switched”
IPv6 Routing - Streaming • Flow Control Labels • Flow Control Labeled packets are “switched” • location of flow label • RSVP Protocol Allows bandwidth reservation • Packet Prioritization • via “Class of Service” • Jumbograms • Up to 4gb packets if MTU allows • Multicast Support • No broadcasting • Allows subscription to a broadcast • “Scope” field for broadcast • via IGMP/ICMP
IPv6 Other Features • Packet Authentication • MD5 - Proposed Default • Packet Encryption • 56bit DES CBC Mode - Propose Default • Plug & Play • Multicast • -built in support • Anycast • Any router
Related Standards • 21 of 51 Existing Internet Standards Affected • DNS • Support for 32bit address records • “AAAA” Records • Routing Protocols • Modification of Interior & Exterior Protocols • ICMPv6 • IGMCav6 • Potentially any upper layer requiring knowledge of IP address
IPX address mapped to IPv6 Unicast Address 0000010 To be defined + existing IPX address 7 128 0 IPv4 address mapped to IPv6 Unicast Address 0000…………...………………………………………………….…0000 0000 32 bit IPv4 address 96 128 0 80 IPv6 Transition • IPv4 Address Translation • Dual Protocol Stacks • IPv6 Tunneled Over IPv4 • IPX/SPX Translation • Extension Headers • 8 Optional Headers Defined • Authentication Header (MD5) - RFC 1827 • Encapsulating Security Payload (56bit DES) - RFC 1829
IPv6 Current Status • Many IPv6 Stacks • Add-ons for MS Windows, Sun, Macs • MS has beta IPv6 stack for NT • Router Operating Systems • Cisco, Bay Networks have IPv6 support • Following are approved RFCs (Dec 98) • RFC 2492 - IPv6 Over ITM RFC 2472 - IPv6 Over PPP • RFC 2470 - IPv6 over TR RFC 2466 - IPv6 ICMPv6 Group • RFC2464 - IPv6 over Ethernet RFC 2463 - ICMP for IPv6 • RFC 2462 - IPv6 Auto configuration RFC 2460 - IPv6 Specification • RFC 2402 - IP Authentication Hdr RFC 2406 - IP Encapsulating Security Payload