Cisco Certified Network Associate (CCNA) Practice Exam

How many total bits are there in an IPv6 address?

1. 64 bits

2. 128 bits

3. 256 bits

4. 32 bits

The correct answer is: 128 bits

An IPv6 address consists of 128 bits. This design allows for a vastly larger address space compared to its predecessor, IPv4, which uses only 32 bits. The increase in bits from IPv4 to IPv6 was motivated by the need to accommodate the dramatically growing number of devices connected to the internet and to provide a solution to the exhaustion of available IPv4 addresses. IPv6 addresses are typically represented in hexadecimal format and are divided into eight groups, each containing 16 bits. The ability to utilize 128 bits significantly enhances the number of unique addresses available, allowing for 2^128 (approximately 340 undecillion) possible addresses, which is essential for the future growth of the internet.