Class IDs

In order to make sure that now two devices share the same public IP, addresses need to be parcelled out.

  • IANA parcels out IP addresses in contiguous chunks called network blocks.

  • Class A: Always begins with 0xxxxxxx

  • Class B: Always begins with 10xxxxxx

  • Class C: Always begins with 110xxxxx

  • Class D: Always begins with 1110xxxx

  • Class E: Always begins with 1111xxxx

IANA #

ARIN #

CIDR #

Subnetting #