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 NSSA Behavior):

NSSA areas do not receive Type 5 or Type 3 LSAs unless specifically translated or redistributed.

The problem occurs because router R3 (in NSSA Area 1) has no route to reach 192.168.3.1 unless a default route is injected.

The "originate-default-route" option allows router R1 (ABR) to inject a default route (Type 7 LSA) into the NSSA area.

Thus, correct answer: A.

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Comprehensive and Detailed Explanation From Exact Extract:

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

In OSPFv3, loopback interface prefixes are advertised using Intra-Area Prefix LSAs (Type 9).

Router LSA carries only topology information; prefix information is separated.

Thus, correct answer: C.

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Comprehensive and Detailed Explanation From Exact Extract:

From Nokia 7750 SR OS Protocol Fundamentals:

“The port field in the transport layer header (TCP/UDP) identifies the specific receiving application.”

Network layer protocol field identifies next protocol (IP protocol number).

Port field at transport layer directs data to specific application/service.

Thus, correct answer is B.

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Comprehensive and Detailed Explanation From Exact Extract:

From Nokia 7750 SR OS Routing Protocols Guide (OSPF Packet Header Information):

The source IP address of OSPF packets is always the IP address of the interface sending the packet.

224.0.0.5 and 224.0.0.6 are destination multicast addresses, not source addresses.

Thus, correct answer: C.

Comprehensive and Detailed Explanation From Exact Extract (Nokia 7750 SR OS Routing Protocols Guide — OSPF Neighbor State Machine):

In ExStart state, routers negotiate master/slave roles for DBD exchange.

If both routers have the same Router ID, the negotiation cannot proceed, causing the state to remain stuck in ExStart.

Thus, correct answer: C.

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Comprehensive and Detailed Explanation From Exact Extract:

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

“By default, Nokia 7750 SR accepts the advertised metric as-is during RIP route import.”

No default override or reset occurs unless configured by policy.

The advertised hop count continues incrementally from peer router.

Thus, correct answer is A.

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