Taxation begins at the time of exercise. The bargain element of a non-qualified stock option is considered compensation and is taxed at ordinary income tax rates. For example, if an employee is granted 100 shares of Stock A at an exercise price of $25, the market value of the stock at the time of exercise is $50.
In the Internet Protocol version 4 (IPv4) [RFC791] there is a field called Protocol to identify the next level protocol. This is an 8 bit field. In Internet Protocol version 6 (IPv6) [RFC2460], this field is called the Next Header field. Values that are also IPv6 Extension Header Types should be listed in the IPv6 Extension Header Types registry at [IANA registry ipv6-parameters].
You will need to obtain new IPv6 addresses in addition to your existing IPv4 address blocks. IPv4 address space that you have today can still be used in a dual IPv4-IPv6 environment. The RIRs all have policies that make it straightforward for an ISP with IPv4 space to apply for and receive IPv6 address space.Pv6, in fact, was specifically designed to fix the address limitations of IPv4. IPv6 addresses have been available for allocation since 1999 and the RIRs, ICANN, ISOC and others are encouraging network operators to apply for IPv6 addresses and implement IPv6 in their networks.