1. Spring 2000John Kristoff1 IPv6 Computer Networks

2. Spring 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. Spring 2000John Kristoff3 IPv6 Header Format

4. Spring 2000John Kristoff4 Options Move Out

5. Spring 2000John Kristoff5 Fragmentation Changes zFragmentation is no long done by routers zHosts musts discover the path MTU zThis is a significant change from IPv4!

6. Spring 2000John Kristoff6 Addressing Changes zUsing IPv4 system y105.220.136.100.255.255.255.255.0.18.128.140.10.255.255 zIPv6 colon hexadecimal notation y69dc:8864:ffff:ffff:0:1280:8c0a:ffff zWith zero compression yff0c:0:0:0:0:0:0:b1 becomes ff0c::b1 yIPv4 addresses start with 96 zeroes zNo more broadcast, new anycast address

7. Spring 2000John Kristoff7 Final Thoughts zWhat’s taking so long? yNAT, CIDR, killer applications zMight help return end-to-end principles zDifficult to upgrade all hosts yDual stacks yEncapsulation zOther benefits and problems?