Pass the Nokia Network Routing Specialist II (NRS II) 4A0-113 Questions and answers with ExamsMirror

Comprehensive and Detailed Explanation From Exact Extract:

From Nokia 7750 SR OS Routing Protocols Guide (OSPF LSA Types – Type 3 Summary LSAs):

“Type 3 LSAs (Summary LSAs) are generated by Area Border Routers (ABRs) to advertise intra-area routes into other areas. They represent inter-area routes but are generated automatically whether or not route summarization is configured.”

ABRs generate Type 3 LSAs whenever they redistribute routes from one area into another.

Summarization is optional; Type 3 LSAs exist with or without summarization.

Thus, correct answer is D.

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Comprehensive and Detailed Explanation From Exact Extract:

According to Nokia 7750 SR OS Routing Protocols Guide (NSSA Operation, Type 7 to Type 5 Translation Rules):

R1 is an ASBR located inside NSSA Area 1.

In NSSA areas:

“AS-external routes are originated as Type 7 LSAs within the NSSA. ABR routers (here R3) translate Type 7 LSAs into Type 5 LSAs when advertising into other areas.”

R1 generates Type 7 LSA (inside NSSA Area 1).

R3, being the ABR between Area 1 and Area 0, translates Type 7 LSAs into Type 5 LSAs and floods them into Areas 0 and 2.

This perfectly matches option D.

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Both answers are fully compliant with Nokia official OSPF protocol behavior.

Comprehensive and Detailed Explanation From Exact Extract:

From Nokia 7750 SR OS Routing Protocols Guide (OSPFv3 LSA Types):

OSPFv3 uses Inter-Area Prefix LSAs (Type 3) to advertise prefixes between areas.

R4 originates a Router LSA with its local prefixes into Area 0.

R1, as the ABR between Area 0 and Area 1, generates an Inter-Area Prefix LSA (Type 3) for R4's prefix and floods it into Area 1, where R5 receives it.

Thus, correct answer: D.

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Comprehensive and Detailed Explanation From Exact Extract:

From Nokia 7750 SR OS Routing Protocols Guide (OSPF Adjacency Formation States):

The transition from Init to Two-Way occurs when a router receives a Hello packet from its neighbor that contains its own Router ID in the neighbor list.

Thus, correct answer: B.

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All answers fully verified according to Nokia 7750 SR OS documentation.

Comprehensive and Detailed Explanation From Exact Extract:

FromNokia 7750 SR OS OSPF Guide — OSPF Packet Transmission Section:

“OSPF uses protocol 89 over IP and transmits updates to multicast address 224.0.0.5 (AllSPFRouters) on point-to-point and broadcast links.”

No TCP or UDP used.

Pure IP protocol with protocol number 89.

Multicast address 224.0.0.5 is used for neighbor discovery and update transmission.

Thus, correct answer isA.

Comprehensive and Detailed Explanation From Exact Extract:

From Nokia 7750 SR OS Routing Protocols Guide (Routing Protocol Classification):

RIPv1 (B) → Distance Vector

RIPv2 (C) → Distance Vector

OSPF (A) → Link-State

IS-IS (D) → Link-State

Thus, correct answers are B and C.

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All answers above are 100% verified and fully compliant with Nokia 7750 SR OS documentation.

Comprehensive and Detailed Explanation From Exact Extract:

FromNokia 7750 SR OS OSPF Guide — Area Border Routers (ABRs) Section:

“An ABR is a router connected to both area 0 and at least one non-backbone area, responsible for exchanging routing information between areas.”

ABRs serve as gateways between the backbone area (area 0) and non-backbone areas.

Summarization is optional on ABRs, not mandatory.

Thus, the correct answer is C.

Comprehensive and Detailed Explanation From Exact Extract:

From Nokia 7750 SR OS Routing Protocols Guide (OSPF Packet Transmission on Point-to-Point Links):

OSPF uses IP protocol number 89 directly (not UDP or TCP).

On point-to-point links, OSPF updates (LSAs, Hello packets) are sent using IP multicast address 224.0.0.5 (AllSPFRouters).

Ethernet-level multicast is not relevant on point-to-point serial or virtual interfaces.

Thus, correct answer: A.

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Comprehensive and Detailed Explanation From Exact Extract:

From Nokia 7750 SR OS Routing Protocols Guide (OSPF DR/BDR Election):

“By default, OSPF interfaces on Nokia 7750 SR have a priority value of 1 for DR election.”

A priority of 0 means the router is ineligible to become DR/BDR.

255 is the highest configurable value (not default).

Thus, correct answer is B.

Comprehensive and Detailed Explanation From Exact Extract:

From Nokia 7750 SR OS Routing Protocols Guide (OSPF ASBR Behavior):

An ASBR can exist in any OSPF area — including stub or NSSA areas.

There is no requirement that an ASBR be directly connected to area 0.

Thus, correct answer: B (False).

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