JN0-363 Exam Dumps - Juniper JNCIS-SP Questions and Answers

To ensure that MPLS traffic-engineered routes are used without affecting IGP routes in the route tables, the mpls-forwarding traffic engineering setting should be used. This setting allows MPLS to influence forwarding without changing the IGP route selection.References:

• MPLS Traffic Engineering, Juniper Networks Documentation
• Traffic Engineering and LSP Optimization, Juniper Networks Documentation

The exhibit shows the output of the commandshow spanning-tree bridge, which provides information about the spanning tree status of the switch. From the output, we can see that the switch has a bridge ID different from the root ID, which implies that this switch is not the root bridge. The "Topology change initiator" field shows ge-0/0/14, which indicates that the last topology change occurred on this interface, and this is also the interface used to reach the root bridge.

References:

• Juniper Networks documentation on Spanning Tree Protocol: Understanding Spanning Tree Protocols

Theno-readvertisepolicy statement is used to prevent a static route from being redistributed into a dynamic routing protocol. This setting ensures that routes that are configured statically are not advertised out via dynamic routing protocols such as OSPF or BGP.

References

• Juniper Networks Technical Documentation on Routing Policy

Referring to the configuration in the exhibit, R1 is set to export the 3rd_Policy to the neighbor at 192.168.1.5. Since 3rd_Policy permits the 10.200.3.0/24 prefix, only that prefix will be advertised to the neighbor.References:

• BGP Policies, Juniper Networks Documentation
• Policy Framework, Juniper Networks Documentation

only 10.200.3.0/24 will be advertised. The neighbor export overrides anything at the group level and protocol level. Policies aren't additive, you can't apply all three at the same time. What if one of them rejected a prefix while the other accepted the same one? You need one to override the other

In Junos OS, traffic engineering extensions for OSPF, which are required for an LSP to use the OSPF link state database for path computations, are not enabled by default. They must be explicitly enabled in the OSPF configuration. Therefore, answer C is correct. Answer B is incorrect and contradicts C. The 'no-cspf' command would disable CSPF (Constrained Shortest Path First), which is used for path computations in MPLS traffic engineering, so it should not be used if you want the LSP to utilize OSPF's link state database for path computations. Therefore, answer A is incorrect. The 'policing' parameter is not relevant to enabling traffic engineering extensions in OSPF, so answer D is incorrect.

References:

• Juniper Networks documentation on OSPF and Traffic Engineering: Configuring OSPF Traffic Engineering

https://www.juniper.net/documentation/us/en/software/junos/ospf/topics/topic-map/configuring-ospf-support-for-traffic-engineering.html

By default, BGP will propagate routes learned from EBGP peers to other IBGP peers. However, due to the BGP split-horizon rule, routes learned from one IBGP peer are notre-advertised to another IBGP peer. This behavior is designed to prevent routing information loops within the same AS.

References:

• Juniper Networks documentation on BGP: BGP Route Propagation and Selection

Wide metrics in IS-IS allow for a larger metric value than what is available with narrow metrics, which supports a maximum of 63. Wide metrics also enable an interface to advertise different metrics for Level 1 and Level 2, allowing for more flexible routing policies and greater scalability in large networks.References:

• IS-IS Wide Metrics, Juniper Networks Documentation
• Configuring IS-IS Wide Metrics, Juniper Networks Documentation

R2 can not forward IBGP learned routes to another IBGP neighbor correct

R3 will learn about Route X from R2 only. R1 is in a separate AS and Route X is advertised to R2 through eBGP. R2 will then advertise the route to R3 using iBGP. R3 cannot learn routes directly from another AS without having a direct eBGP session with that AS.References:

• BGP Route Propagation and Selection, Juniper Networks Documentation
• Understanding iBGP and eBGP Route Distribution, Juniper Networks Documentation

https://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first-ospf/13684-12.html#anc13

Neighbors Stuck in Exstart/Exchange State The problem occurs most frequently when you attempt to run OSPF between a Cisco router and another vendor router. The problem occurs when the maximum transmission unit (MTU) settings for neighboring router interfaces do not match. If the router with the higher MTU sends a packet larger that the MTU set on the neighboring router, the neighbor router ignores the packet. When this problem occurs, the output of the show ip ospf neighbor command displays output similar to what is shown in this figure.

A mismatched Maximum Transmission Unit (MTU) setting on OSPF interfaces can cause routers to get stuck in the ExStart state. OSPF requires that both sides of a link have the same MTU to form a full adjacency.References:

• OSPF Troubleshooting, Juniper Networks Documentation
• MTU and OSPF, Juniper Networks Documentation

In MPLS, multiple paths can be merged if they share the same egress router. In the given scenario, traffic from Network 1 to Network 3 and Network 4 can be engineered to follow the same label-switched path (LSP) within the MPLS network until they reach the last common point before diverging to their respective destinations.

As for R3 performing label operations, in a typical MPLS network, intermediate routers (like R3) perform label swapping. They replace the incoming label with a new label before forwarding the packet along the LSP. A label pop operation is typically performed by the egress router in the case of an ultimate hop pop (UHP), where it removes the MPLS label before delivering the packet to the final destination outside the MPLS domain.

References

• Juniper Networks Technical Documentation on MPLS
• Understanding MPLS Label Operations (Swap, Push, and Pop) - Juniper Networks