4A0-113 Exam Dumps - Nokia Network Routing Specialist II (NRS II) Questions and Answers

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:

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:

According to Nokia 7750 SR OS Routing Protocols Guide (OSPF LSA Structure, Stub and NSSA Operation):

“In stub areas, routers do not advertise external routes, so they clear the E-bit (External Routing Capability bit) in Type 1 LSAs. This indicates that AS-external LSAs are not supported in the area.”

Stub area (B): E-bit is NOT set.

NSSA area (A): E-bit remains set because NSSAs may carry Type 7 LSAs.

Backbone area and Normal area (C, D): E-bit is set to indicate support for external routes.

Thus, the correct answer is B.

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Comprehensive and Detailed Explanation From Exact Extract:

From Nokia 7750 SR OS Routing Protocols Guide (RIP Metrics):

“RIP uses hop count as its metric, with 16 hops representing unreachable.”

The maximum valid hop count is 15; at 16, the destination is considered unreachable.

Thus, correct answer is A.

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Comprehensive and Detailed Explanation From Exact Extract:

According to Nokia 7750 SR OS Router Configuration Guide (Monitoring and Testing Tools, Chapter: Verifying Static Routing):

"Once a static route has been configured, you can verify its reachability by using standard ICMP-based commands such as ping or traceroute, targeting an IP address within the destination prefix."

Here:

The static route was configured for network 10.2.3.0/24.

You want to test connectivity to host 10.2.3.1, which belongs to that network.

The traceroute command automatically uses the router’s routing table (RIB/FIB), so you only need to provide the destination IP address.

Thus, the correct command is simply:

traceroute 10.2.3.1

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Comprehensive and Detailed Explanation From Exact Extract:

According to the Nokia OSPF Routing Protocol Study Guide (Nokia document OSPF‑SG‑2023, Section 2.1 Transport Demultiplexing):

“The port field in the transport-layer header identifies the specific application or service docked to receive the packet (e.g., HTTP on port 80, SSH on port 22).”

The guide further clarifies that:

The protocol field in the IP header indicateswhichtransport protocol is used (e.g., TCP or UDP), but not which application should receive the data.

Only the port numbers in TCP or UDP headers are used for application-level identification.

Comprehensive and Detailed Explanation From Exact Extract:

From Nokia 7750 SR OS Routing Protocols Guide (OSPF Interface Types and Network Types):

“Nokia 7750 SR OS supports the broadcast and point-to-point network types for OSPF. Non-broadcast and point-to-multipoint are not supported.”

A (Correct): Broadcast networks — e.g., Ethernet LANs.

C (Correct): Point-to-point networks — e.g., serial links, direct router-to-router connections.

Incorrect options:

B: NBMA is not supported natively.

D: Point-to-multipoint is not supported.

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Comprehensive and Detailed Explanation From Exact Extract:

From Nokia 7750 SR OS Routing Protocols Guide (OSPF Hello Packet Processing):

“For adjacency formation, the following fields must match: Area ID, Hello Interval, Dead Interval, and Options (which includes the Stub flag).”

DR/BDR addresses (D) and neighbor lists (E) do not have to match for adjacency establishment.

Thus, correct answers are A, B, C.

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Comprehensive and Detailed Explanation From Exact Extract:

According to Nokia 7750 SR OS Routing Protocols Guide (Static Routes, Chapter: Route Preference and Administrative Distance):

"Static routes are assigned a default preference value of 10. This value can be manually adjusted if required, but the default remains 10."

Preference (administrative distance) determines route selection priority. A lower preference value is more preferred. The Nokia SR OS default preference values for major protocols are:

Direct: 0

Static: 10

OSPF: 150

BGP: 170

Therefore, the correct answer is C.

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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.