JN0-351 Exam Questions & Answers

Option A is correct. Creating multiple areas in OSPF can help to reduce the convergence time . This is because changes in one area do not affect other areas, so fewer routers need to run the SPF algorithm in response to a change.

Option D is correct. Creating multiple areas in OSPF can help to reduce Link State Advertisement (LSA) flooding across the network. This is because LSAs are not flooded out of their area of origin.

Ais correct because generated routes require a contributing route.A contributing route is a route that matches the destination prefix of the generated route and has a valid next hop1.A generated route is only installed in the routing table if there is at least one contributing route available2. This ensures that the generated route is reachable and useful.If there is no contributing route, the generated route is not added to the routing table2.

Bis correct because generated routes show a next hop in the routing table.A generated route inherits the next hop of its primary contributing route, which is the most preferred route among all the contributing routes2.The next hop of the generated route can be either an IP address or an interface name, depending on the type of the contributing route2.The next hop of the generated route can also be modified by a routing policy3.

Option B is correct.Filter-based forwarding (FBF), also known as Policy Based Routing (PBR), uses the forwarding routing instance type12.

Option C is correct.Routing Information Base (RIB) groups are used to copy routes from one routing table to another34.In the context of FBF, RIB groups can be used to copy routes from the inet.0 routing table34.

Option A is incorrect.FBF does not use the no-forwarding routing instance type15.

Option D is incorrect.RIB groups are not used to hide routes in the inet.0 routing table34.They are used to share or copy routes between different routing tables34.

A tunnel is a connection between two computer networks, in which data is sent from one network to another through an encrypted link. Tunnels are commonly used to secure data communications between two networks or to connect two networks that use different protocols.

Option B is correct, because tunnel endpoints must have a valid route to the remote tunnel endpoint. A tunnel endpoint is the device that initiates or terminates a tunnel connection. For a tunnel to be established, both endpoints must be able to reach each other over the underlying network.This means that they must have a valid route to the IP address of the remote endpoint1.

Option D is correct, because tunnels add additional overhead to packet size. Tunnels work by encapsulating packets: wrapping packets inside of other packets. This means that the original packet becomes the payload of the surrounding packet, and the surrounding packet has its own header and trailer. The header and trailer of the surrounding packet add extra bytes to the packet size, which is called overhead.Overhead can reduce the efficiency and performance of a network, as it consumes more bandwidth and processing power2.

Option A is incorrect, because BFD can be used to monitor tunnels. BFD is a protocol that can be used to quickly detect failures in the forwarding path between two adjacent routers or switches. BFD can be integrated with various routing protocols and link aggregation protocols to provide faster convergence and fault recovery. BFD can also be used to monitor the connectivity of tunnels, such as GRE, IPsec, or MPLS.

Option C is incorrect, because IP-IP tunnels are stateless. IP-IP tunnels are a type of tunnels that use IP as both the encapsulating and encapsulated protocol. IP-IP tunnels are simple and easy to configure, but they do not provide any security or authentication features. IP-IP tunnels are stateless, which means that they do not keep track of the state or status of the tunnel connection. Stateless tunnels do not require any signaling or negotiation between the endpoints, but they also do not provide any error detection or recovery mechanisms.

1:What is Tunneling? | Tunneling in Networking2:What Is Tunnel In Networking, Its Types, And Its Benefits?: [Configuring Bidirectional Forwarding Detection] : [IP-IP Tunneling]

In BGP, routing policies are used to control the flow of routing information between BGP peers1.

Option C suggests that import policies are applied after the RIB-In table.This is correct because import policies in BGP are applied to routes that are received from a BGP peer, before they are installed in the local BGP Routing Information Base (RIB-In)1.The RIB-In is a database that stores all the routes that are received from all peers1.

Option D suggests that export policies are applied after the RIB-Local table.This is correct because export policies in BGP are applied to routes that are being advertised to a BGP peer, after they have been selected from the local BGP Routing Information Base (RIB-Local)1.The RIB-Local is a database that stores all the routes that the local router is using1.

Therefore, options C and D are correct.