4A0-100 Exam Preparation Material | Nokia IP network and Service fundamentals

Explanation:
The Nokia 7750 SR architecture separates its operations into control plane and data plane functions. The Data Plane includes hardware components responsible for forwarding traffic at line rate.
These components include:
MDA (Media Dependent Adapter) C interfaces with physical media.
IOM (Input/Output Module) C performs high-speed packet forwarding and processing.
XMA (eXpandable Media Adapter) C extends port capacity and media support.
The Control Plane includes the CPM (Control Processor Module), which is responsible for running routing protocols, managing configuration, system operations, and other control-related functions. The CPM does not participate in data forwarding and is thus not part of the data plane.
Reference: Nokia SRA Study Guide, Chapter: "System Architecture C 7750 SR Components"
Nokia IP Networks and Services Fundamentals C Section: Control and Data Plane Functions in SR Architecture

Explanation:
OSPF (Open Shortest Path First) is a Link-State protocol that uses:
Cost (based on bandwidth) as its metric.
Dijkstra’s algorithm to compute shortest path trees.
Supports hierarchical routing with areas (e.g., Area 0 as backbone).
Routers exchange LSAs, not full routing tables.
Option D is FALSE C OSPF does not use hop-count. That’s a RIP (Distance Vector) feature.
Reference: Nokia IP Routing Guide C Section: “OSPF Operation and Area Design” RFC 2328 C OSPFv2 Protocol Specification

Explanation:
VLAN Stacking, also known as Q-in-Q tunneling, is a technology that allows multiple customers to use overlapping VLAN IDs while being transported over a shared service provider network.
Key Concepts:
Customer VLAN (C-VLAN): The VLAN used by the customer in their own network.
Service VLAN (S-VLAN): The VLAN used by the service provider to encapsulate the customer VLAN.
When VLAN stacking is applied:
A customer's Ethernet frame already tagged with a C-VLAN is encapsulated with an additional outer S-VLAN tag.
This way, multiple customers can use the same C-VLAN ID, but remain isolated by the unique S-VLAN
assigned to them by the service provider.
Why Other Options Are Incorrect:
A. VLAN Trunking: Used to carry multiple VLANs over a single physical link but doesn’t allow reuse of VLAN IDs across customers.
C. VLAN Tagging: Refers to the general process of adding a VLAN tag; it doesn't provide the isolation needed across shared infrastructure.
D. VLAN Routing: Refers to Layer 3 routing between VLANs, not to ID reuse or transport over a
shared provider backbone.
Reference: Nokia Service Architecture and VPNs Study Guide C Section: “Q-in-Q VLAN Stacking” IEEE 802.1ad Standard C Provider Bridges (Q-in-Q)

Explanation:
Route summarization (a.k.a. supernetting) is the process of combining multiple contiguous subnets into a single summarized route, which:
Reduces routing table entries
Enhances scalability and efficiency
Minimizes instability by localizing route changes
Option A is false because it describes subnetting, not summarization. Summarization works in the opposite direction C combining smaller routes into a larger one.
Reference: Nokia IP Routing Guide C Chapter: “Route Summarization Techniques” Cisco CCNA C IP Routing Concepts

Explanation:
The Ingress Label Edge Router (LER) is the first router that:
Receives an unlabeled IP packet.
Applies an MPLS label based on its forwarding decision.
Forwards it into the MPLS core.
Option A is correct C Ingress LER does MPLS label push.
Option B (Egress LER) C removes labels at the end of the path.
Option C (LSR) C switches labels, but doesn’t push them onto unlabeled packets.
Option D C is not a specific MPLS role.
Reference: Nokia IP/MPLS Fundamentals Guide C Label Operations
RFC 3031 C MPLS Architecture