1. LOGO IPv6 Application Analysis Xi Chen scotor317@gmail.com

2. IPv6 Addressing Overall Application Scenario

3. IPv6 Addressing IPv6 Addressing Architecture x:x:x:x:x:x:x:x x is a 16 bits hexadecimal field E.g.: 2001:0000:1234:0000:0000:C1C0:ABCD:0876 Case insensitive 2001:0000:1234:0000:0000:c1c0:abcd:0876 Leading zeros in a field are optional: 2001:0:1234:0:0:C1C0:ABCD:876 Successive fields of 0 are represented as ::, but only once in an address 2001:0:1234::C1C0:ABCD:876 Not valid: 2001::1234::C1C0:ABCD:876 Other examples: FF02:0:0:0:0:0:0:1 => FF02::1 0:0:0:0:0:0:0:1 => ::1 0:0:0:0:0:0:0:0 => ::

4. IPv6 Addressing IPv6 Addressing Allocation AllocationBinary PrefixFraction of address space Unicast0011/8 Link Local address space 1111 1110 101/1024 Site Local address space 1111 1110 111/1024 Multicast1111 1/256 The Anycast addressing use the same address allocation as Unicast. Example: Unicast 2080:0:0:0:8:800:200C:317A=1080::8:800:200C:317A Multicast FF01:0:0:0:0:0:0:101=FF01::101

5. IPv6 Addressing Interface-IDFPTLA-IDResNLA-IDSLA-ID ≥3≤138241664 Public Topology Site Topology Interface Identifier Network Portion Node Portion FP= Format Prefix (= 001 for globally aggregated unicast addresses) TLA-ID= Top-level aggreation identifier RES= Reserved for future use NLA= Next-level aggregation identifier SLA-ID= Site-level aggregation identifier Interface ID= Interface identifier IPv6 Addressing Format

6. IPv6 Addressing  MAC Address: 0000:0B0A:2D51  In binary: 00000000 00000000 00001011 00001010 00101101 01010001  Insert FFFE between Company-ID and Node-ID 00000000 00000000 00001011 11111111 11111110 00001010 00101101 01010001  Set U/L bit to 1 00000010 00000000 00001011 11111111 11111110 00001010 00101101 01010001  Resulting EUI-64 Address: 0200:0BFF:FE0A:2D51 Interface ID

7. IPv6 Addressing Unicast Addressing

8. IPv6 Addressing Anycast Addressing

9. IPv6 Addressing Group-ID11111111flgs 84112 128 bit scope 4 First 3 bits set to 0 Last bit defines address type: 0 = Permanent (or well-known) 1 = Locally assigned (or transient) Defines address scope 0Reserved 1Node-local scope 2Link-local scope 5Site-local scope 8Organization local scope EGlobal scope FReserved Multicast Addressing Format

10. IPv6 Addressing Multicast Addressing

11. IPv6 Addressing Link local Addressing  Examples FE80::0060:08FF:FEB1:7EA2 FE80::200:CFF:FE0A:2C51 Interface-ID11111110100 105464 128 bit

12. IPv6 Addressing Site Local Addressing Interface-ID11111110110 105464 128 bit Subnet-ID (SLA-ID) 16  Examples FEC0::0060:08FF:FEB1:7EA2 FEC0::200:CFF:FE0A:2C51

13. ICMPv6 – Type 1: Destination Unreachable – Type 2: Packet Too Big (MTU) – Type 3: Time Exceeded – Type 4: Parameter Problem – Type 128/129: Echo request/Echo reply

14. ICMPv6 Code0 - no route to destination 1 - communication with destination administratively prohibited 2 - (not assigned) 3 - address unreachable 4 - port unreachable Type=1CodeChecksum As much of invoking packet as will fit without the ICMPv6 packet exceeding the minimum IPv6 MTU 32 bits Unused UnusedThis field is unused for all code values. It must be initialized to zero by the sender and ignored by the receiver. Destination Unreachable

15. ICMPv6 CodeSet to 0 by the sender and ignored by the receiver MTUThe maximum transmission unit of the next- hop link Type=2CodeChecksum As much of invoking packet as will fit without the ICMPv6 packet exceeding the minimum IPv6 MTU 32 bits MTU Packet too big(MTU)

16. ICMPv6 Code0 – Hop limit exceeded in transit 1 – Fragment reassembly time exceeded Type=3CodeChecksum As much of invoking packet as will fit without the ICMPv6 packet exceeding the minimum IPv6 MTU 32 bits Unused UnusedThis field is unused for all code values. It must be initialized to zero by the sender and ignored by the receiver. Time Exceeded

17. ICMPv6 Code0 - erroneous header field encountered 1 - unrecognized Next Header type encountered 2 - unrecognized IPv6 option encountered Type=4CodeChecksum As much of invoking packet as will fit without the ICMPv6 packet exceeding the minimum IPv6 MTU 32 bits Pointer PointerIdentifies the octet offset within the invoking packet where the error was detected. The pointer will point beyond the end of the ICMPv6 packet if the field in error is beyond what can fit in the maximum size of an ICMPv6 error message. As much of invoking packet as will fit without the ICMPv6 packet exceeding the minimum IPv6 MTU Pointer Parameter Problem

18. ICMPv6 Code0 IdentifierAn identifier to aid in matching Echo Replies to this Echo Request. May be zero. SNA sequence number to aid in matching Echo Replies to this Echo Request. May be zero. DataZero or more octets of arbitrary data. Type=128Code=0Checksum Data 32 bits IdentifierSequence Number Echo Request

19. ICMPv6 Code0 IdentifierThe identifier from the invoking Echo Request message. SNThe sequence number from the invoking Echo Request message DataThe data from the invoking Echo Request message. Type=129Code=0Checksum Data 32 bits IdentifierSequence Number Echo Reply

20. Neighbor Discovery Defines five ICMPv6 packets 1.Router solicitation (RS) 2.Router advertisement (RA) 3.Neighbor solicitation (NS) 4.Neighbor advertisement (NA) 5.Redirect

21. Neighbor Discovery Router solicitation (RS) Type=133CodeChecksum Reserved 32 bits Options....

22. Neighbor Discovery Router advertisement (RA) Type=134CodeChecksum Reachable Time 32 bits Hop LimitMOReservedRouter lifetime Retransmit Timer Options....

23. Neighbor Discovery RS and RA procedure

24. Neighbor Discovery Router advertisement in routers

25. Neighbor Discovery Type=135CodeChecksum Reserved 32 bits Target address Options.... Neighbor solicitation (NS)

26. Neighbor Discovery Type=136CodeChecksum Reserved 32 bits Target address Options.... RSO Neighbor advertisement (NA)

27. Neighbor Discovery Redirect Type=137CodeChecksum Reserved 32 bits Target address Options.... Destination address

28. Neighbor Discovery A B C D E F G Default GW-List A B C ICMP Redirect to Router B Path used with Default Gateway "A" Host 3 Sent data to Host 3 using Default GW "A" Redirect traffic via Router B Redirect Procedure

29. Neighbor Discovery  Check neighbor cache for existing next-hop entry for particular destination  Check whether destination is on- or off-link  On-link: Sent directly to destination  Off-link: Sent to default router  Identify link-layer address of next-hop Next Hop Discovery

30. Neighbor Discovery  Uses Neighbor solicitation & advertisements  Node checks neighbor cache first  If no entry exists, node creates IP entry with state INCOMPLETE  Node then sends NS to solicited-node multicast address  Source address of NS is a unicast address  Receiving node responds with NA indicating it‘s own link-level address  Soliciting node updates neighbor cache entry from INCOMPLETE to REACHABLE upon receiption of NA Address Resolution

31. Neighbor Discovery  2 ways to verify neighbor reachability:  Using hints from upper-layer protocols  From responses to neighbor solicitations  Forward direction communication (FDC) must be possible for a neighbor to be REACHABLE  FDC is verified if forward progress is being made by an upper- layer protocol (i.e. TCP, receiption of TCP acks)  If no verification can be received from upper-layer protocols (like UDP):  Node actively probes neighbors to determine reachability state  Probes are sent in conjunction with traffic. No traffic, no probes!  Probe is neighbor solicitation (NS)  Neighbor advertisement (NA) reply is expected to establish FDC Neighbor Unreachability Detection

32. Neighbor Discovery  Must be performed by all nodes  Performed before assigning a unicast address to an interface  Performed on interface initialization  Not performed for anycast addresses  Link must be multicast capable  New address is called "tentative" as long as duplicate address detection takes place 1.Interface joins all-nodes multicast group 2.Interface joins solicited-node multicast group 3.Node sends (one) NS with Target address = tentative IP address Source address = unspecified (::) Destination address = tentative solicited-node address If address already exists, the particular node sends a NA reply with Target address = tentative IP address Destination address = tentative solicited-node address If soliciting node receives NA reply with target address set to the tentative IP address, the address must be duplicate Duplicate Address Detection

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