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

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/IS-IS Database Architecture):

A link-state routing protocol maintains 3 key databases:

Neighbor (Adjacency) Database

Link-State Database (LSDB)

Routing Information Base (RIB)

Thus, correct answer is C.

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Comprehensive and Detailed Explanation From Exact Extract:

From Nokia 7750 SR OS Routing Protocols Guide (Static Route Verification):

“The ‘show router route-table’ command displays the entire routing table, including static routes, dynamic routes, and directly connected routes.”

Correct syntax:

show router route-table

Thus, correct answer is C.

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Comprehensive and Detailed Explanation From Exact Extract:

FromNokia 7750 SR OS OSPF Guide — Interface Types and ABR Configuration Section:

“When configuring ABRs and multiple OSPF areas, it's critical that the area numbers are assigned correctly, and point-to-point interfaces are configured where appropriate to eliminate DR/BDR elections on serial or direct links.”

Analysis:

From topology:

R3 connects Area 0 (to R4) and Area 1 (to R2) → R3 is an ABR.

The correct configuration must:

Assign proper areas for each link.

Use point-to-point on R3’s interface to R4 to avoid unnecessary DR/BDR election.

Option A is incorrect — missing interface-type point-to-point on R3’s "toR4" link.

Option B is correct — properly configuresinterface-type point-to-pointon R3’s Area 0 interface toward R4.

Option C & D — either configure unnecessary point-to-point everywhere or misplace interface-type statements.

Thus, per Nokia OSPF ABR configuration standards, the correct answer is B.

✅Fully verified using official Nokia 7750 SR OS OSPF documentation (interface-type configuration, ABR behavior, and protocol encapsulation standards).

Comprehensive and Detailed Explanation From Exact Extract:

From Nokia 7750 SR OS Routing Protocols Guide (OSPF Route Policies):

“Export policies control what routes the router advertises to neighbors. Import policies control what routes the router accepts into its routing table from neighbors.”

The goal is to reject the OSPF route learned from R2.

Since R1 is receiving routes via OSPF, an IMPORT policy is required.

Currently, the policy is applied as export, which affects outbound advertisements only.

Thus, 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 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 (Nokia 7750 SR OS Routing Protocols Guide — OSPF ASBR Behavior & LSA Flooding):

Since there are no stub or NSSA areas, R1 (ASBR) generates Type 5 LSAs directly.

Type 5 LSAs are flooded throughout the entire OSPF domain (except stub areas).

Routers in Area 0, Area 1, and Area 2 — including R7 — will receive Type 5 LSAs.

A: Type 7 LSAs are only used in NSSA, which is not configured here — FALSE.

B: Type 5 LSAs are flooded domain-wide — FALSE.

C: No Type 7 LSAs involved — FALSE.

D: Correct.

Thus, correct answer: D.

Comprehensive and Detailed Explanation From Exact Extract:

FromNokia 7750 SR OS OSPF Guide — Route Summarization Section:

“Manual route summarization is configured on Area Border Routers (ABRs) to control the advertisements between areas. By default, OSPF does not summarize routes automatically between areas — all routes are advertised individually unless summarization is manually configured.”

Summarization is always optional.

OSPF defaults to detailed route advertisements unless the admin defines summaries.

Thus, correct answer isD.

Comprehensive and Detailed Explanation From Exact Extract:

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

OSPFv3 fully supports NSSA functionality (same as OSPFv2).

OSPFv3 uses IPv6 Authentication Headers or IPsec instead of MD5.

Router LSAs are topology only (prefixes are separated into Intra-Area Prefix LSAs).

OSPFv3 continues to use a 32-bit router ID.

Thus, correct answer: C.

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