IPv4 address exhaustion

• IPv4's 32-bit address space provides only about 4.3 billion addresses
• Regional Internet Registries (RIRs) exhausted their free IPv4 pools starting in 2011
• NAT, CIDR and private addressing delayed exhaustion but added complexity and did not solve it

Benefits beyond address space

• 128-bit addresses provide a practically inexhaustible address space – no NAT required
• Simplified, fixed-size header speeds up router processing
• Built-in address autoconfiguration (SLAAC) and no broadcast traffic (multicast replaces it)