Which two statements describe characteristics of IPv6 unicast addressing? (Choose two.)
A.
Global addresses start with 2000::/3.
B.
Link-local addresses start with FE00:/12.
C.
Link-local addresses start with FF00::/10.
D.
There is only one loopback address and it is ::1.
E.
If a global address is assigned to an interface, then that is the only allowable address for the
interface.
Unicast is communication between a single sender and a single receiver over a network. The term exists in contradistinction to multicast, communication between a single sender and multiple receivers, and anycast, communication between any sender and the nearest of a group of receivers in a network.
The loopback address is a unicast localhost address. If an. application in a host sends packets to this address, the IPv6 stack will loop these packets back on the same virtual interface. Loopback addresses are expressed in the following form: ::1. or, with their appropriate prefix, ::1/128
P712
An IPv6 address is represented as eight groups of four hexadecimal digits, each group representing 16 bits (two octets). The groups are separated by colons (:). An example of an IPv6 address is:
2001:0db8:85a3:0000:0000:8a2e:0370:7334
The hexadecimal digits are case-insensitive, but IETF recommendations suggest the use of lower case letters. The full representation of eight 4-digit groups may be simplified by several techniques, eliminating parts of the representation.
Leading zeroes
Leading zeroes in a group may be omitted.[1] Thus, the example address may be written as:
2001:db8:85a3:0:0:8a2e:370:7334
Groups of zeroes
One or more consecutive groups of zero value may be replaced with a single empty group using two consecutive colons (::).[1] Thus, the example address can be further simplified:
2001:db8:85a3::8a2e:370:7334
The localhost (loopback) address, 0:0:0:0:0:0:0:1, and the IPv6 unspecified address, 0:0:0:0:0:0:0:0, are reduced to ::1 and ::, respectively. This two-colon replacement may only be applied once in an address, because multiple occurrences would create an ambiguous representation.
Dotted-quad notation
During the transition of the Internet from IPv4 to IPv6 it is typical to operate in a mixed addressing environment, and for this purpose a special notation has been introduced to express IPv4-mapped and IPv4-compatible IPv6 addresses by writing the final 32 bits of an address in the familiar IPv4 dotted-quad notation. For example, the IPv4-mapped IPv6 address ::ffff:c000:0280 is usually written as ::ffff:192.0.2.128, thus expressing clearly the original IPv4 address that was mapped to IPv6.