Protocol: collection of network data rules
Includes transmission rules
Internet Protocol version 4 (IPv4)
Internet Protocol version 6 (IPv6)
Replaces IPv4 (future)
IPv4 and IPv6 not directly compatible
Advantages
128-bit number for addresses
2128 addresses: 34 followed by 37 zeros
Packet format change eliminates unnecessary fields
Adds fields for security, other optional information
Shorthand notation system for expressing addresses (complex eight groups of 16 bits)
Colon hexadecimal or colon hexNote: hexadecimal = base 16