Pass the Juniper JNCIS-SP JN0-363 Questions and answers with CertsForce

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.

When establishing an EBGP session, it's necessary to specify both the local AS number and the local address that the session will use. The local address is required for establishing the TCP connection for BGP. The local AS must be specified to identify the autonomous system of the router.

https://supportportal.juniper.net/s/article/EX-Identify-the-Root-Bridge-in-a-Spanning-Tree-STP-network?language=en_US The root bridge in a spanning-tree network is the bridge with the smallest or the lowest bridge ID.

In the absence of a manually configured priority, the Spanning Tree Protocol (STP) elects the root bridge based on the lowest bridge ID, which is a combination of the priority and the MAC address. The device with the lowest MAC address will have the lowest bridge ID and thus be elected as the root bridge.

References

Juniper Networks Technical Documentation on STP

The AS path is a BGP attribute that lists the autonomous systems (AS) that routing information has passed through to get to a destination. It is used to detect and prevent routing loops by checking if the router's own AS number is in the path.

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.

A router’s priority for becoming the designated router is indicated by an arbitrary number from 0 through 127, which you configure on the IS-IS interface. The router with the highest priority becomes the designated router for the area (Level 1, Level 2, or both), also configured on the IS-IS interface. If routers in the network have the same priority, then the router with the highest MAC address is elected as the designated router. By default, routers have a priority value of 64.

https://www.juniper.net/documentation/us/en/software/junos/is-is/topics/concept/routing-protocol-is-is-security-designated-router-understanding.html

A Level 1 router can become adjacent with the Level 1 and Level 1-2 (L1/L2) router. A Level 2 router can become adjacent with Level 2 or Level 1-2 (L1/L2) router. There is no adjacency between L1 only and L2 only router. HOWEVER: If two routers are in different areas, they can only form a Level 2 adjacency. As such, two routers in different areas can NOT form a Level 1 adjacency. If you want two routers to form a Level 1 adjacency, they have to be in the same area.

IS-IS (Intermediate System to Intermediate System) operates at two levels: Level 1 and Level 2. Level 1 routers are only aware of their own area's topology, while Level 2 routers have knowledge of the topology across areas. A Level 1 router cannot form an adjacency with a Level 2 router unless the Level 2 router is also operating as a Level 1 router (Level 1-2 router). Level 2 routers can form adjacencies regardless of their area IDs because Level 2 operates at the domain level and is used to interconnect different IS-IS areas.

References

Juniper Networks Technical Documentation on IS-IS

IS-IS Levels and Areas Explanation - Juniper Networks

Given the RSVP Signaled Service Provider MPLS Core network shown in the exhibit, only a single Label Switched Path (LSP) is required to support all four networks because MPLS can use label stacking to multiplex multiple LSPs over a single physical path. Therefore, one LSP can be established through the MPLS core, and all networks can use this LSP with different label stacks.

The no-readvertise policy 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

The router identifier is used by BGP and OSPF to identify the routing device from which a packet originated. The router identifier usually is the IP address of the local routing device. If you do not configure a router identifier, the IP address of the first interface to come online is used. This is usually the loopback interface. Otherwise, the first hardware interface with an IP address is used

In OSPF, if a router ID is not manually configured, Junos OS will automatically select the router ID based on the highest IP address of any of the router’s loopback interfaces. If no loopback interface exists, the highest IP address of any active interface will be used. Therefore, answer C is correct.