1. TDC 375 Winter 2002John Kristoff1 Network Protocols IPv6

2. TDC 375 Winter 2002John Kristoff1 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. TDC 375 Winter 2002John Kristoff1 IPv6  Standardized in RFC 2460  Extends Addresses from 32 to 128 bits  Streamlined header format  Routers no longer fragment packets  New flow labeling capability  Enhanced options design

4. TDC 375 Winter 2002John Kristoff1 IPv6 Header Format

5. TDC 375 Winter 2002John Kristoff1 Options Move Out

6. TDC 375 Winter 2002John Kristoff1 Various Protocol Changes  ICMP Streamlined  IGMP now part of ICMP  Changes to upper layers  New DNS record type AAAA  RIPv6  OSPFv6

7. TDC 375 Winter 2002John Kristoff1 Fragmentation Changes  Fragmentation is no longer done by routers  Hosts musts discover the path MTU  This is a significant change from IPv4!

8. TDC 375 Winter 2002John Kristoff1 Addressing Changes  Using IPv4 dotted decimal notation  105.220.136.100.255.255.255.255.0.18.128.140.10.255.255  IPv6 uses colon hexadecimal notation  69dc:8864:ffff:ffff:0:1280:8c0a:ffff  With zero compression  ff0c:0:0:0:0:0:0:b1 becomes ff0c::b1  IPv4 addresses start with 96 zeroes  No more broadcast, new anycast address

9. TDC 375 Winter 2002John Kristoff1 Address Assignment  Standard assignments  IPv4 compatibility  IPX addresses  Link, site and multicast addresses  Auto configuration  Serverless autoconfiguration is possible  Simple renumbering is possible

10. TDC 375 Winter 2002John Kristoff1 Making the Transition  6Bone - current testbed  Dual stacks  Tunnelling  Address Translation  Lots of software changes!  Will take years, but may be taking off now

11. TDC 375 Winter 2002John Kristoff1 Final Thoughts  What  s taking so long?  NAT, CIDR, killer applications  Might help return end-to-end principles  Difficult to upgrade all hosts  Other benefits and problems?