CCST - Cisco Certified Support Technician IPv4 vs. IPv6 Addressing Questions and Answers 1 — Questions and Answers
Question 1: A network technician is configuring a new device on an IPv6-enabled network. The device needs to automatically configure its own IP address without the use of a DHCP server. Which IPv6 feature allows for this?
- NAT64
- SLAAC (Correct answer)
- Anycast
- DHCPv6
Correct answer: SLAAC
Stateless Address Autoconfiguration (SLAAC) is a key feature of IPv6 that allows a device to automatically generate its own unique IPv6 address by combining the network prefix provided by a router with its own interface identifier (often derived from the MAC address). This process does not require a stateful server like DHCP.
Question 2: What is the primary reason for the development and adoption of IPv6 over IPv4?
- Faster packet processing due to a more complex header.
- The exhaustion of the 32-bit IPv4 address space. (Correct answer)
- Native support for broadcast messaging.
- Simplified address notation using decimal numbers.
Correct answer: The exhaustion of the 32-bit IPv4 address space.
The primary motivation for creating IPv6 was the depletion of the available IPv4 address pool. IPv4 uses a 32-bit address, allowing for approximately 4.3 billion unique addresses, which is insufficient for the growing number of internet-connected devices. IPv6 uses a 128-bit address, providing a vastly larger address space.
Question 3: A support technician is examining IP packet headers and notices a significant difference between IPv4 and IPv6. Which of the following fields is present in an IPv4 header but has been removed from the main IPv6 header to improve efficiency?
- Version
- Source Address
- Header Checksum (Correct answer)
- Hop Limit
Correct answer: Header Checksum
The IPv6 header was simplified for more efficient processing by routers. One of the fields removed from the main IPv6 header is the Header Checksum. Error checking is now expected to be handled by upper-layer protocols (like TCP/UDP) and the link layer, reducing the processing load on routers.
Question 4: How are IPv6 addresses typically represented in human-readable format?
- Four decimal numbers separated by periods.
- Eight hexadecimal numbers separated by colons. (Correct answer)
- A single 128-bit decimal number.
- Six hexadecimal numbers separated by hyphens.
Correct answer: Eight hexadecimal numbers separated by colons.
IPv6 addresses are 128 bits long and are written as eight groups of four hexadecimal digits, with the groups separated by colons. For example: 2001:0db8:85a3:0000:0000:8a2e:0370:7334.
Question 5: A company is transitioning to an IPv6-only internal network but still needs to allow its users to access services on the IPv4 internet. Which technology is specifically designed to facilitate this communication between IPv6 and IPv4 networks?
- SLAAC
- ARP
- NAT64 (Correct answer)
- Broadcast
Correct answer: NAT64
NAT64 is a translation mechanism that allows IPv6-only clients to communicate with IPv4-only servers. A NAT64 gateway translates IPv6 packets into IPv4 packets and vice versa, enabling compatibility between the two protocols during the transition period.
Question 6: Which of the following statements accurately describes a key difference in how IPv4 and IPv6 handle network-wide messages?
- IPv4 uses broadcast messages, while IPv6 has eliminated broadcast in favor of multicast and anycast. (Correct answer)
- IPv6 relies exclusively on broadcast messages for address resolution.
- IPv4 has no mechanism for sending a message to all hosts on a subnet.
- Both IPv4 and IPv6 use identical broadcast mechanisms for all network-wide communication.
Correct answer: IPv4 uses broadcast messages, while IPv6 has eliminated broadcast in favor of multicast and anycast.
IPv4 uses broadcast messages to send a packet to all devices on a local network segment. This can be inefficient. IPv6 eliminates the concept of broadcast and instead uses more efficient multicast messages to communicate with specific groups of devices (e.g., all routers or all nodes on a link). IPv6 also introduces anycast addressing.
CCST - Cisco Certified Support Technician IPv4 vs. IPv6 Addressing Questions and Answers 1
A network technician is configuring a new device on an IPv6-enabled network.
The device needs to automatically configure its own IP address without the use of a DHCP server.
Which IPv6 feature allows for this?