Introduction to IPv6 Network & Application Passakon Prathombutr Next Generation Internet (NGI) National Electronics and Computer Technology Center

2/19 Needs for IPv6 Unlike Y2K IPv4-1970, IPv Exhaustion of IP (v4) addresses Why not IPv5? –“5” becomes stream protocol, ST, assigned in version field of header. Enhance features

3/19 Technological Imperatives for Adoption Need Killer Application? Network Address Translation (NAT) –Not for IPSec, QoS, VoIP, Peer-to-Peer Dynamic Host Configuration Protocol (DHCP) Classless Inter-Domain Routing (CIDR)

4/19 What is IPv6? Internet Protocol Version 6 designed by IETF to replace current IP (IPv4) More address spaces (128-bits) New header design and features

5/19 40 bytes 20 bytes IPv4 IPv vers hlen TOS total length identification flags flag-offset TTL protocol header checksum source address destination address options and padding vers traffic class flow-label payload length next header hop limit source address destination address Removed (6) ID, flags, flag offset TOS, hlen header checksum Changed (3) Added (2) Expanded total length => payload protocol => next header TTL => hop limit traffic class flow label address 32 to 128 bits Header comparison

6/19 IPv6 Changes Source and destination addresses 32 bits (4 bytes)128 bits (16 bytes) IPsec support OptionalStandard Identification of packet flow for QoS handling by routers None in headerIncluded in header IPv4IPv6 Fragmentation By both routers and sending host Only by sending host Header checksum IncludedNot included Header optional data Included Moved to extension headers

7/19 IPv6 Changes IPv4IPv6 IP address resolution method Broadcast ARP request frames Multicast Nghbrhd. Solicitation messages Managing local subnet group membership IGMP Multicast Listener Discovery (MLD) Determine best default gateway ICMP Router Discovery (opt.) ICMPv6 Router Solicitation & Adv. messages (req.) Sending traffic to all nodes on subnet Broadcast addresses Multicast address

8/19 IPv6 Changes IPv4IPv6 Manually or through DHCP Automatic AAAAA or A 6 IN-ADDR.ARPAIP6.INT 576-byte (possibly fragmented) 1280 byte (no fragmentation) Configuration Host address resource records used to map to IP addresses Pointer resource records in DNS domain used to map to host Packet size support

9/19 What it Means Simplified header –Faster router processing –Less overhead Efficient option processing No fragmentation –Reduced load on routers –Easier to implement in hardware –Easy Layer 3 switching of IP Minimum link MTU is 1280 bytes

10/19 IPv6 Address Structure Interface ID –Unique identifier for each host (48-bit MAC address + some padding) –Structure of a ‘Provider Based Unicast’ (like IPv4 with CIDR) –No more ‘classes’ (A,B,C,D,E) –More ‘granularity’ than IPv4 or IPv4 CIDR –No need to specify subnet mask

11/19 Major Improvement of IPv6 Header No Option field. Replaced by extension header. Result in a fixed length, 40- byte IP header. No header checksum. Result in fast processing. No fragmentation at intermediate nodes. Result in fast IP forwarding.

12/ bit IPv6 Address 3FFE:085B:1F1F:0000:0000:0000:00A9: groups of 16-bit hexadecimal numbers separated by “ : ” 3FFE:85B:1F1F::A9:1234 :: = all zeros in one or more group of 16-bit hexadecimal numbers Leading zeros can be removed

13/19 Prefix Allocation TypePrefix (binary bits)Range Global (+anycast)0012xxx to 3xxx Link-local FE8x to FEBx Site-local FECx to FEFx Multicast FFxx Link-local: Unreachable from other sites, equivalent to IPv4 private addr. Site-local: Used to communicate with neighbor node on the same link. Global Allocation: 2001::/16Sub-TLA Assignment (by APNIC, ARIN, RIPE) 2002::/166to4 (simply generated from 1 public IPv4 address) 3FFE::/166bone (e.g., NECTEC got 3FFE:4016::/32)

14/19 Benefits of IPv6 Improve efficiency in routing and packet handling –Large addressing space and network prefixes – short and scalable routing table –Header format is simpler than that of the IPv4 header – good for 64-bit processors Support Plug and Play address auto- configuration/ renumbering – Good for mobile IP wireless devices, and home appliances. – Easier to transit from one provider to another.

15/19 Benefits of IPv6 (cont.) Support for embedded IPSec – Encapsulating Security Payload (ESP) and Authentication Header (AH) are parts of extension headers Improve support for multicast – No more broadcast addresses Eliminate the need for NAT Support for widely deployed routing protocols e.g., OSPFv3, IS-ISv6, RIPng and BGP4+

16/19 Techniques for Transition Dual stack Between IPv6 islands via IPv4 cloud – IPv6-over-4 configured tunnel, 6to4, 6over4, ISATAP, Tunnel broker (freenet6, Hurricane Electric, TILAB) Between IPv6 and IPv4 – DSTM(Dual-Stack Transition Mechanism), NAT-PT(Network Address Translation- Protocol Translation), SIIT (Stateless IPv6- IPv4 Translator), BIS(Bump-In-the-Stack), BIA(Bump-In-the-API), TCP-UDP relay

17/19 IPv4 Network IPv4 Network 6to4 Tunneling 6to4 network Tunnel 6to4 router 6to4 router 6to4 network IPv IPv6 2002:C096:F018::1/ :C096:F018::2/128 IPv IPv6 2002:CA39:7CBA::1/ :CA39:7CBA::2/128 IPv6 packet Src. 2002:CA39:7CBA::2/128 Dest. 2002:C096:F018::2/128 IPv4 packet Src Dest IPv6 packet Src. 2002:CA39:7CBA::2/128 Dest. 2002:C096:F018::2/128