What is IPv6? (1)

The answer to IPv4 address space problem
IP address changed from 32bit to 128bit
32bit is smaller than worldwide human population
IPv4 address shortage is a bondage to new application areas
IPv4 addresses will run out around 2010-20?
4x10^9 -> 3.4x10^38
4 billion -> 340 undecillion

A new starting point
IPv4: used for 20 years, minimal implementation lacks almost everything
IPv6: new standard features like multicast, PMTUD, IPsec, autoconfig
Leverage the availability of advanced technologies

An answer to routing table size issue
IPv4: portable address (->CIDR), result in 50K entries
IPv6: full CIDR + well-structured address assignment
restricts DFZ routes to 8K