Tags: #◇Computer Science #◇NSCOM02 #◇Networking #◇Routing Protocols #◇SDN #◇Reviewer #◇Finals
NSCOM02 Comprehensive Finals Reviewer
◇Overview
This reviewer consolidates Advanced Network Communications and Routing (NSCOM02). Core topics cover interior and exterior routing protocols, Distance-Vector routing (Bellman-Ford algorithm, Routing Information Protocol - RIP, Count-to-Infinity problem, Split Horizon with Poison Reverse), Link-State routing (Dijkstra's shortest path, Open Shortest Path First - OSPF, Link-State Advertisements - LSAs, hierarchical areas), Interdomain Routing (Border Gateway Protocol - BGP, Autonomous Systems, path vector attributes, peering vs transit), Software-Defined Networking (SDN architecture, separation of Control Plane and Data Plane, OpenFlow protocol, centralized controllers), and network telemetry/management (ICMP diagnostic messages, Simple Network Management Protocol - SNMP MIBs).
◇1. Routing Protocols Master Comparison Matrix
| Protocol | Type / Paradigm | Underlying Algorithm | Metric | Convergence Speed | Scalability / Scope |
|---|---|---|---|---|---|
| RIPv2 | Interior (IGP), Distance-Vector | Bellman-Ford | Hop count (max 15 hops; 16 = ) | Slow (periodic 30s updates) | Small networks ( hops) |
| OSPFv2 | Interior (IGP), Link-State | Dijkstra's Shortest Path First | Cost (typically inverse of bandwidth) | Fast (event-driven LSAs) | Large enterprise networks (Hierarchical Areas) |
| BGP-4 | Exterior (EGP), Path-Vector | Policy-based Path Vector | Policy rules, AS-PATH length, Local Pref | Moderate | Global Internet interconnect between ASes |
| SDN (OpenFlow) | Centralized Control Plane | Global controller computation | Programmable software policies | Real-time flow table pushes | Data centers, cloud networks, enterprise WANs |
◇2. SDN Architecture: Control Plane vs Data Plane
◇3. High-Yield Exam Checklist
- In RIP, what hop count represents unreachable / infinity? Exactly 16 hops.
- What is the role of OSPF Area 0? It is the Backbone Area to which all other non-backbone areas must connect.
- In BGP, what attribute prevents routing loops between Autonomous Systems? The AS-PATH attribute (if a router sees its own AS number in the list, it drops the route!).
- Does SDN move the routing decision logic off the physical switches? YES, physical switches only execute high-speed packet forwarding according to flow rules pushed by the central controller.
- What SNMP operation is pushed asynchronously by an agent to alert the management station of an emergency event? SNMP Trap (or Inform).
◇References & Navigation
- Previous Topic: ◇CSNETWK
- Next Topic: ◇NSCOM03
- Prerequisites: ◇Routing Protocols, RIP, OSPF, BGP, SDN, OpenFlow
- Cross-Curricular Connections: ◇NSSECU1
ACTIVE RECALL VERIFICATION
Select an answer to verify conceptual comprehension and reveal the technical rationale.
What mechanism in Distance-Vector routing prevents a router from advertising a learned route back out the same interface through which it originally received it?
What is the maximum valid hop count supported by the Routing Information Protocol (RIP) before a destination is declared unreachable?
In OSPF, what type of router connects one or more non-backbone areas directly to the backbone Area 0?
Which BGP path attribute list guarantees loop-free interdomain routing by recording every Autonomous System traversed by a route advertisement?
In Software-Defined Networking (SDN), what protocol commonly operates across the Southbound interface between the centralized controller and the data-plane forwarding switches?