The output shown in the exhibit is the result of the command ''show ip bgp neighbor 10.36.1.4 received-routes'', which displays all received routes (both accepted and rejected) from the specified neighbor.

Option A is correct, because the routes displayed have traversed one or more autonomous systems. This can be seen from the AS_PATH attribute, which shows the sequence of AS numbers that the route has passed through. For example, the route 10.0.0.0/8 has an AS_PATH of 65001 65002, which means that it has traversed AS 65001 and AS 65002 before reaching the local router.

Option B is correct, because the output shows routes that were received prior to the application of any BGP import policies. This can be seen from the fact that some routes have a status code of ''r'', which means that they are rejected by an import policy. The ''received-routes'' keyword shows the routes coming from a given neighbor before the inbound policy has been applied. To see the routes after the inbound policy has been applied, the ''routes'' keyword should be used instead.

Option C is incorrect, because the output does not show routes that are active and rejected by an import policy. The status code of ''r'' means that the route is rejected by an import policy, but it does not mean that it is active. The status code of ''>'' means that the route is active and selected as the best path. None of the routes in the output have both ''>'' and ''r'' status codes.

Option D is incorrect, because the routes displayed are not being learned from an IBGP peer. An IBGP peer is a BGP neighbor that belongs to the same AS as the local router. The output shows that the neighbor 10.36.1.4 has a remote AS of 65001, which is different from the local AS of 65002. Therefore, the neighbor is an EBGP peer, not an IBGP peer.

A) On R1, enable Level 1 on the ge-0/0/1 interface.In IS-IS, both levels (Level 1 and Level 2) are enabled by default when you enable IS-IS on an interface1.Level 1 systems route within an area2.If the destination is outside an area, Level 1 systems route toward a Level 2 system2. Therefore, enabling Level 1 on the ge-0/0/1 interface on R1 would allow packets to reach from R1 to R3.

D) On R3 enable Level 1 on the ge-0/0/4 interfaceSimilarly, enabling Level 1 on the ge-0/0/4 interface on R3 would allow packets to reach from R1 to R3.

These explanations are based on the IS-IS configuration documents and learning resources available at Juniper Networks1and Cisco34.

The default keepalive time for BGP is60 seconds1.The keepalive time is the interval at which BGP sends keepalive messages to maintain the connection with its peer1.If the keepalive message is not received within the hold time, the connection is considered lost1.By default, the hold time is three times the keepalive time, which is180 seconds1.

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.

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]