Routing Protocols

Correct Answer: Link State Advertisements (LSA)

Link State Advertisements (LSA) is the correct answer because in a rapidly expanding network, the LSA mechanism keeps track of the network's state and can quickly adapt to changes, thus preventing scalability issues. The LSA also reduces bandwidth usage by only communicating changes rather than the entire routing table with each update. On the other hand, Distance-Vector routes data packets on the basis of the shortest number of intermediate routers but it does not allow for accurate control over the routing path, therefore it is less scalable and efficient. Path-Vector, while it does keep track of the entire path that a packet takes to arrive at its destination, is not the most efficient way to manage a rapidly growing network, as it does not adapt as well to changes in network topology. Lastly, Flooding involves broadcasting data out to every node in the network, which is clearly not scalable in a large network due to the heavy data traffic it generates.

Correct Answer: OSPF

The correct answer is OSPF (Open Shortest Path First). This is because OSPF uses a link-state routing protocol which results in a complete topographic database of the network. This database prevents unnecessary routing through non-optimal paths and minimizes administrative overhead by reducing the need for continual manual updates. RIPv1 and RIPv2 use distance-vector routing protocols, which can cause routing loops and increased network traffic. This would increase, rather than decrease, administrative overhead. Lastly, BGP (Border Gateway Protocol) is primarily used for routing between autonomous systems on the internet, rather than within a single network. Therefore, it would not be the best choice for the situation described in the question.

Correct Answer: RIPv2

The best routing protocol for a router with limited memory and processing power is RIPv2. RIPv2, or Routing Information Protocol version 2, is a distance-vector routing protocol that is simple and requires less processing power and memory compared to other protocols. OSPF (Open Shortest Path First) and EIGRP (Enhanced Interior Gateway Routing Protocol) are link-state routing protocols that require more memory and processing power as they hold a complete topology of the network. BGP (Border Gateway Protocol) is a path-vector protocol used for routing between autonomous systems and is more complex, resulting in high resource utilization.