d. 128
IPv6 uses 128-bit hexadecimal addresses and has built-in security and QoS features. An IPv6 address is 128 bits rather than the 32 bits in an IPv4 address. This length increases the number of possible addresses from about 4 billion in IPv4 to 3.4 x 1038 addresses (that’s 34 followed by 37 zeros!) in IPv6. Unless IP addresses are assigned to every star in the universe, it’s safe to say enough IPv6 addresses will be available.
Unlike IPv4 addresses, which are specified in dotted decimal notation in 8-bit sections, IPv6 addresses are specified in hexadecimal format in 16-bit sections separated by a colon, as in this example: 2001:1b20:302:442a:110:2fea:ac4:2b. If one of the 16-bit numbers doesn’t require four hexadecimal digits, the leading 0s are omitted. Furthermore, some IPv6 addresses contain consecutive 0s in two or more 16-bit sections, so a shorthand notation is used to eliminate consecutive 0 values.
The IPSec protocol provides authentication and encryption. In IPv4, it must be added to a network, but it’s already incorporated in IPv6. Authentication ensures that the sender and receiver of data packets are known to each other and have permission to send and receive data. Encryption makes the data in packets unreadable except to the computers involved in the transmission. IPv6 is autoconfiguring, which means there’s no IP address to assign and no subnet mask to determine. Two types of autoconfiguration are available in IPv6, stateless and stateful.
2. The subnet mask of an IP address does which of the following?.
b. Defines network and host portions of an IP address A 32-bit number in dotted decimal format, consisting of a string of eight or more binary 1s followed by a string of 0s, that determines which part of an IP address is the network ID and which part is the host ID. A binary 1 in the subnet mask signifies