4A0-100 Exam Dumps - Nokia IP Networksand Services Fundamentals

TheInternet Assigned Numbers Authority (IANA)is responsible for managing theglobal IP address pool, along with:

Allocating blocks ofIP addresses to Regional Internet Registries (RIRs)such as ARIN (North America), RIPE NCC (Europe), APNIC (Asia-Pacific), etc.

Managingautonomous system numbers (ASNs).

OverseeingDNS root zonesand protocol parameters.

IANAdoes not assign IPs directly to enterprises or individuals— those tasks are delegated toRIRs and ISPs.

Option A & B:Enterprises and residential allocations are handled by ISPs or RIRs.

Option D:North American IPs are managed byARIN, not IANA.

Option C is correct– IANA manages theglobal IP address allocationhierarchy.

Tier 1 ISPs: Haveglobal reachabilityand exchange traffic via peering. Theydo not payfor transit.

Tier 2 ISPs: Purchasetransit services from Tier 1and provide transit to Tier 3 or other Tier 2 ISPs.

Tier 3 ISPs: Providelast-mileconnectivity to end users and donot provide transit services.

Option A is correct– Tier 1 and Tier 2provide transit services.

Link-State routing protocols(e.g.,OSPF,IS-IS) operate by:

Each routerflooding link-state advertisements (LSAs)throughout the network.

Every router constructs acomplete map of the network topology.

Then each router runs theSPF algorithmto compute optimal paths.

Option C is correct– routers know theentire network topology.

Option A isDistance Vector behavior(e.g., RIP).

Option B isnot efficient or accurate for Link-State.

Option D –hop-countis used inDistance Vector(e.g., RIP).

A layered protocol stack is designed to simplify network communication by separating functionalities into distinct layers. Each layer has a defined role and communicates with the layers directly above and below it. The main benefits of this model include:

Simplified design and implementation: Developers can focus on one layer without needing to understand the entire system.

Flexibility: New protocols can be developed and inserted at specific layers without redesigning the whole stack.

Interoperability: Standard interfaces allow different systems and vendors to work together.

Isolation of functions: Errors and updates can be managed within one layer without impacting others.

However,reducing protocol overhead is not a primary goalof this model. In fact, the encapsulation and interaction between layers can sometimesintroduce extra overhead. This overhead is a trade-off accepted to gain the other benefits listed above.