1. Autumn 2000John Kristoff1 Computer Networks IPv6

2. Autumn 2000John Kristoff2 Motivation The primary motivation from changing the IP datagram format is to increase the size of the useable address space from 32 bits to 128 bits. Secondary reasons include routing improvements, simplicity in header format and even to bring back some of the end-to-end principles that are being lost due to NAT and firewalls.

3. Autumn 2000John Kristoff3 IPv6 ÑStandardized in RFC 2460 ÑExtends Addresses from 32 to 128 bits ÑStreamlined header format ÑRouters no long fragment packets ÑNew flow labeling capability ÑEnhanced options design

4. Autumn 2000John Kristoff4 IPv6 Header Format

5. Autumn 2000John Kristoff5 Options Move Out

6. Autumn 2000John Kristoff6 Various Protocol Changes ÑICMP Streamlined ÑIGMP now part of ICMP ÑChanges to upper layers ÑNew DNS record type AAAA ÑRIPv6 ÑOSPFv6

7. Autumn 2000John Kristoff7 Fragmentation Changes Ñ Fragmentation is no long done by routers Ñ Hosts musts discover the path MTU Ñ This is a significant change from IPv4!

8. Autumn 2000John Kristoff8 Addressing Changes ÑUsing IPv4 dotted decimal notation Ñ 105.220.136.100.255.255.255.255.0.18.128.140.10.255.255 ÑIPv6 uses colon hexadecimal notation Ñ69dc:8864:ffff:ffff:0:1280:8c0a:ffff ÑWith zero compression Ñff0c:0:0:0:0:0:0:b1 becomes ff0c::b1 ÑIPv4 addresses start with 96 zeroes ÑNo more broadcast, new anycast address

9. Autumn 2000John Kristoff9 Address Assignment ÑStandard assignments ÑIPv4 compatibility ÑIPX addresses ÑLink, site and multicast addresses ÑAuto configuration ÑServerless autoconfiguration is possible ÑSimple renumbering is possible

10. Autumn 2000John Kristoff10 Making the Transition Ñ6Bone - current testbed ÑDual stacks ÑTunnelling ÑAddress Translation ÑLots of software changes! ÑWill take years, but may be taking off now

11. Autumn 2000John Kristoff11 Final Thoughts  What ’ s taking so long? ÑNAT, CIDR, killer applications ÑMight help return end-to-end principles ÑDifficult to upgrade all hosts ÑOther benefits and problems?