IP Address Allocation History

• 1981 - IPv4 protocol published
• 1985 ~ 1/16 of total space
• 1990 ~ 1/8 of total space
• 1995 ~ 1/4 of total space
• 2000 ~ 1/2 of total space

• this despite increasingly intense conservation efforts

  • PPP / DHCP address sharing
  • CIDR (classless inter-domain routing)
  • NAT (network address translation)
  • plus some address reclamation

• theoretical limit of 32-bit space: ~4 billion devices practical limit of 32-bit space: ~250 million devices

  • (see draft-durand-huitema-h-density-ratio)

Notes: