1. IPv6 Current version of the Internet Protocol is Version 4 (v4)
Earlier versions were not implemented
The next version will be Version 6 (v6)
No v5 was implemented
Informally called IPng (Next Generation)
IPv6 is Already Defined
Continuing improvements in v4 may delay its adoption

2. IPv6
IPv6 will raise the size of the internet address from 32 bits to 128 bits
Now running out of IP addresses
Will solve the problem
But current work-arounds are delaying the need for IPv6 addresses

3. IPv6 Improved Security Improved Quality of Service (QoS)
But, through IPsec, v4 is being upgraded in security as well
Improved Quality of Service (QoS)
But under IETF Differentiated Services (diffserv) initiative, IPv4 is being upgraded in this area as well

4. IPv6 Extension Headers IPv4 Headers are complex
IPv6 basic header is simple
Extension headers for options
Basic Header
Extension Header 1
Extension Header 2

5. IPv6 Extension Headers Basic header has 8-bit Next Header field
Identifies first extension header or says that payload follows
Basic Header NH
Extension Header 1
Extension Header 2

6. IPv6
Extension Headers
Each extension header also has 8-bit Next Header field
Identifies next extension header or says that payload follows
Basic Header
Extension Header 1 NH
Extension Header 2

7. IPv6
Extension Headers
Next header field is an elegant way to allow options
Easy to add new extension headers for new needs
Basic Header
Extension Header 1 NH
Extension Header 2