Which Cisco IOS command is used to assign an IPv6 address to an interface?
Correct Answer: A
Detailed Explanation: IPv6 is the most recent version of the Internet Protocol and is designed to address the limitations of IPv4, including the exhaustion of available addresses. Configuring IPv6 addresses on Cisco devices is a fundamental skill, and the command used to assign an IPv6 address to an interface in Cisco IOS is "ipv6 address". When you enter the "ipv6 address" command in interface configuration mode, you specify the IPv6 address and, optionally, the prefix length. For example, the command: ipv6 address 2001:0DB8:ACAD:1::1/64 assigns the IPv6 address 2001:0DB8:ACAD:1::1 with a prefix length of 64 bits to the interface. This process is analogous to configuring an IPv4 address using the "ip address" command, though IPv6 addresses are represented in a different format and use hexadecimal notation. The "ipv6 address" command is part of the suite of commands introduced to support IPv6 on Cisco routers and switches. This command not only assigns an address to an interface but also enables IPv6 processing on that interface if it was not already enabled. With IPv6, devices have a vastly larger address space, improved routing efficiency, and enhanced support for multicast and anycast addressing, among other benefits. IPv6 configuration on Cisco devices requires an understanding of several new concepts compared to IPv4. For instance, IPv6 does not use broadcast addresses; instead, it relies on multicast addresses for similar functionality. Additionally, IPv6 includes features such as stateless address autoconfiguration (SLAAC) and neighbor discovery, which are essential for efficient network management in large-scale deployments. By using the "ipv6 address" command, network administrators can ensure that interfaces are correctly configured to participate in IPv6 networks. This is particularly important as the global transition to IPv6 continues due to the limitations inherent in the IPv4 addressing scheme. The use of IPv6 not only future-proofs a network but also allows for more efficient routing and improved support for mobile and IoT devices. Moreover, proper IPv6 configuration is crucial for maintaining interoperability between IPv4 and IPv6 networks. Many networks operate in dual-stack mode, where both IPv4 and IPv6 are enabled, and devices must be configured correctly to handle traffic in both protocols. The "ipv6 address" command plays a key role in this process by ensuring that interfaces have unique IPv6 addresses and can communicate effectively within an IPv6 network. For the CCNA exam, a thorough understanding of IPv6 addressing and configuration is essential. Questions on IPv6 address assignment, the differences between IPv4 and IPv6, and the implications for routing and network design are common. Mastery of the "ipv6 address" command demonstrates not only technical proficiency but also an awareness of modern network trends and the need to support both legacy and emerging protocols. In summary, the "ipv6 address" command is the correct and primary command used in Cisco IOS to assign an IPv6 address to an interface. Its use is fundamental in configuring devices to operate within IPv6 networks, ensuring proper addressing, routing, and communication in today’s increasingly interconnected world.
This CCNA practice question helps students prepare for Cisco networking certification exams by testing knowledge of network fundamentals, routing, switching, and network security concepts.