Which three statements are correct when comparing Mobile IPv6 and Mobile IPv4 support? (Choose three.)
Click on the arrows to vote for the correct answerA. B. C. D. E. F.
Mobile IPv6 and Mobile IPv4 are protocols that allow a mobile node (MN) to maintain its IP address and session information while moving between different networks. Here are the explanations for each statement:
A. Mobile IPv6 does not require a foreign agent, but Mobile IPv4 does. Mobile IPv4 requires a foreign agent (FA) to be present on the foreign network to act as an intermediary between the MN and the home agent (HA) on the home network. The FA is responsible for forwarding packets between the MN and the HA, which can introduce additional latency and complexity. Mobile IPv6, on the other hand, uses a different approach called "route optimization" that eliminates the need for an FA. In route optimization, the MN communicates directly with the correspondent node (CN) on the foreign network using a new header called the "routing header."
B. Mobile IPv6 supports route optimization as a fundamental part of the protocol; IPv4 requires extensions. As explained above, Mobile IPv6 uses route optimization as a fundamental part of the protocol, while Mobile IPv4 requires extensions to support it. Route optimization allows the MN to communicate directly with the CN on the foreign network, which can improve performance and reduce latency.
C. Mobile IPv6 and Mobile IPv4 use a directed broadcast approach for home agent address discovery. Both Mobile IPv6 and Mobile IPv4 use a "home agent address discovery" mechanism to locate the HA on the home network. In Mobile IPv6, the MN sends a multicast message to the "home agent anycast address" to discover the nearest HA. In Mobile IPv4, the MN sends a directed broadcast message to the home network to discover the HA.
D. Mobile IPv6 makes use of its own routing header; Mobile IPv4 uses only IP encapsulation. As mentioned earlier, Mobile IPv6 uses a new header called the "routing header" to support route optimization. The routing header contains information about the path the packet should take through the network, and it allows the MN to communicate directly with the CN on the foreign network. Mobile IPv4, on the other hand, uses IP encapsulation to tunnel packets between the MN and the HA.
E. Mobile IPv6 and Mobile IPv4 use ARP for neighbor discovery. Mobile IPv6 and Mobile IPv4 both use the Address Resolution Protocol (ARP) to discover the MAC addresses of devices on the local network. ARP is used to map an IP address to a MAC address, which is necessary for communication at the link layer.
F. Mobile IPv4 has adopted the use of IPv6 N. This statement is incorrect. Mobile IPv4 does not use IPv6 Neighbor Discovery (ND). Rather, it uses a similar mechanism called "Agent Advertisement and Solicitation" (AAS) to discover the FA and HA on the local network.