Cisco Certified Network Associate (CCNA) Practice Exam

What is a characteristic of IPv6 addresses?

1. They are 32 bits long

2. They use decimal notation

3. They are represented as hexadecimal pairs

4. They have a fixed subnet mask

The correct answer is: They are represented as hexadecimal pairs

The choice indicating that IPv6 addresses are represented as hexadecimal pairs is correct. IPv6 addresses consist of 128 bits and are typically expressed in hexadecimal notation to simplify representation. This notation is formed as eight groups of four hexadecimal digits, separated by colons. The representation in hexadecimal allows for a more compact and readable form compared to binary or decimal. For instance, an IPv6 address might look like this: 2001:0db8:85a3:0000:0000:8a2e:0370:7334, showcasing the use of hexadecimal digits to represent the various segments of the address. This characteristic is particularly relevant because it distinguishes IPv6 from its predecessor, IPv4, which is composed of four octets represented in decimal format. The fixed length and structure of IPv6 enhance its capability to accommodate a significantly larger number of unique addresses, a necessity due to the exponential growth of IP-connected devices.