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].
In IPv4, Host (A) records are used to map an IP address to a host name. DNS is still used in IPv6, but Host (A) records are not used by IPv6 addresses. Instead, IPv6 uses AAAA resource records, which are sometimes referred to as Quad A records. The domain ip6.arpa is used for reverse hostname resolution.ne of the things that has caused IPv6 adoption to take so long is that IPv6 is not generally compatible with IPv4 networks. As a result, a number of transition technologies use tunneling to facilitate cross network compatibility. Two such technologies are Teredo and 6to4.