IPv4 Addressing, Long Term Solution: IPv6 And Subnet Example

Long Term Solution: IPv6

• IPv6, or IPng (IP – the Next Generation) uses a 128-bit address space, yielding

     340,282,366,920,938,463,463,374,607,431,768,211,456 

    possible addresses.

• IPv6 has been slow to arrive

• IPv4 revitalized by new features, making IPv6 a luxury, and not a desperately needed fix

• IPv6 requires new software; IT staffs must be retrained

• IPv6 will most likely coexist with IPv4 for years to come.

• Some experts believe IPv4 will remain for more than 10 years.

IPv4 Addressing

Subnet Mask

•One solution to the IP address shortage was thought to be the subnet mask.

•Formalized in 1985 (RFC 950), the subnet mask breaks a single class A, B or C network in to smaller pieces.

Short Term Solutions: IPv4 Enhancements

•CIDR (Classless Inter-Domain Routing) – RFCs 1517, 1518, 1519, 1520

•VLSM (Variable Length Subnet Mask) – RFC 1009

•Private Addressing - RFC 1918

•NAT/PAT (Network Address Translation / Port Address Translation) – RFC

 

IPv4 versus IPv6

•IP version 6 (IPv6)  has been defined and developed.  

•IPv6 uses 128 bits rather than the 32 bits currently used in IPv4.

•IPv6 uses hexadecimal numbers to represent the 128 bits.

Subnet Example

Network address 190.52.0.0 with /16 

network mask

Using Subnets: subnet mask 255.255.255.0 

or /24

Subnet Example

Subnet 0 (all 0’s subnet) issue:  The 

address 

of the subnet, 190.52.0.0/24 is the same 

address as the major network, 

190.52.0.0/16.

Last subnet (all 1’s subnet) issue:  The 

broadcast address for the subnet, 

190.52.255.255 is the same as the 

broadcast 

address as the major network, 

190.52.255.255.

Subnet Example

Given the Class B address 

190.52.0.0

Subnet Example

Using the 3rd octet, 190.52.0.0 was divided into:

190.52.1.0    190.52.2.0    190.52.3.0    190.52.4.0

190.52.5.0    190.52.6.0    190.52.7.0    190.52.8.0

190.52.9.0    190.52.10.0  190.52.11.0  190.52.12.0

190.52.13.0  190.52.14.0  190.52.15.0  190.52.16.0

190.52.17.0  190.52.18.0  190.52.19.0  and so on ...