Everything in this manual to date refers to IPv4 (IP version 4) addressing. The world is running out -- well, technically-speaking ''has'' run out -- of IPv4 addresses. Various strategies have been adopted by ISPs to obscure and work-round this issue and much of the world is still running on IPv4. | Everything in this manual to date refers to IPv4 (IP version 4) addressing. The world is running out -- well, technically-speaking ''has'' run out -- of IPv4 addresses. Various strategies have been adopted by ISPs to obscure and work-round this issue and much of the world is still running on IPv4. |