Master Juniper JN0-351 Exam with Reliable Practice Questions

Correct : B

The exhibit shows the output of the commandshow ospf neighbor, which displays information about the OSPF neighbors on a router1.

The output shows that the OSPF neighbor with the address 172.26.1.1 and the interface ge-0/0/3.0 is in the Exstart state1.

The Exstart state is the fourth state in the OSPF neighbor formation process, after Down, Init, and 2-Way states2.In this state, the OSPF neighbors establish a master-slave relationship and exchange database description (DBD) packets, which contain summaries of their link-state databases2.

The most common reason for OSPF neighbors to be stuck in the Exstart state is an MTU mismatch between the interfaces3.MTU stands for maximum transmission unit, which is the largest size of a packet that can be transmitted on a network segment4.If the MTU values of two OSPF neighbors are different, they may not be able to exchange DBD packets successfully, as some packets may be dropped or fragmented due to their size exceeding the MTU limit3.

To solve this problem, you need to ensure that the MTU values of both OSPF neighbors are the same or compatible.You can use the commandshow interfacesto display the MTU value of an interface5. You can also use the commandpingwith thedo-not-fragmentoption to test the MTU size between two routers.You can change the MTU value of an interface by using the commandset interfaces interface-name mtu mtu-valuein configuration mode5.

Correct : A, B

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.

Correct : B, C

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.

Correct : A, B

Option A is correct. For traffic to be sent through a GRE tunnel, there must be a route that directs the traffic into the tunnel. This is typically accomplished through the use of a static route or a dynamic routing protocol.

Option B is correct. All intermediary devices must have a route to the tunnel endpoints34. In real-world scenarios, the tunnel endpoints for a tunnel going over the Internet must have globally reachable internet addresses. Otherwise, intermediate routers in the Internet cannot forward the tunneled packets.

Correct : B, C

Bis correct because the loops do not exist is one of the conditions that are verified by the receiving router to ensure that the received BGP route is valid.A loop in BGP means that a route has been advertised by the same AS more than once, which can cause routing instability and inefficiency1.To prevent loops, BGP uses the AS-path attribute, which lists the AS numbers that a route has traversed from the origin to the destination2.The receiving router checks the AS-path attribute of the received route and discards it if it finds its own AS number in the list2. This way, BGP avoids accepting routes that contain loops.

Cis correct because the next hop is reachable is one of the conditions that are verified by the receiving router to ensure that the received BGP route is valid.The next hop is the IP address of the next router that is used to forward packets to the destination network3.The receiving router checks the next hop attribute of the received route and verifies that it has a valid route to reach it3.If the next hop is not reachable, the received route is not usable and is rejected by the receiving router3. This way, BGP ensures that only feasible routes are accepted.