Exam Description

The 642-661 BGP exam is a qualifying exam for the CCIP certification. The 642-661 BGP exam tests material covered under the Configuring BGP on Cisco Routers (BGP) v 3.1 course. The BGP exam assesses a candidate's understanding of the theory of BGP, ability to configure BGP on Cisco IOS routers, and skills with troubleshooting on BGP. As a routing protocol, BGP is one of the underlying foundations of the Internet and new-world technologies.

Exam Topics

The following information provides general guidelines for the content likely to be included on the BGP exam. However, other related topics may also appear on any specific delivery of the exam.

BGP Overview

Introduction to BGP
Given a network scenario, identify appropriate BGP usage and its limitations

BGP Session Establishment
Given a typical BGP network scenario, describe the concept of BGP neighbors and the neighbor session establishment procedures

BGP RouteProcessing
Given a diagram of an operational BGP network, describe interdomain route processing, route propagation and BGP path selection

Basic BGP Configuration
Given a network consisting of multiple domains, successfully configure BGP

Monitoring and Troubleshooting BGP
Given a configured BGP network, verify proper operation and perform the steps necessary to correct basic BGP configuration errors

Route Selection Using Policy Controls

Multi-Homed BGP Networks

Given a customer scenario where connections to multiple ISPs must be supported, describe the need for influencing BGP route selection

AS-Path Filters

Given a customer scenario where connections to multiple ISPs must be supported, successfully configure BGP to influence route selection using AS path filters

Prefix-List Filters

Given a customer scenario where connections to multiple ISPs must be supported, successfully configure BGP to influence route selection using prefix-list filters

Outbound Route Filtering

Given an operational BGP network, use outbound route filtering to minimize the impact of BGP routing updates on router resources

Route-Maps as BGP Filters

Given a typical BGP network, correctly configure BGP to influence route selection using route maps

Implementing Changes in BGP Policy

Given a typical BGP network, configure the route-refresh feature to minimize the impact of expediting BGP policy updates

Route Selection Using Attributes

BGP Path Attributes

• List BGP path attributes and functionality of each attribute Influencing BGP Route Selection with Weights
• Given a customer scenario where multiple connections must be supported, successfully configure BGP to influence route selection using the weight attribute

BGP Local Preference

Given a customer scenario where multiple connections must be supported, successfully configure BGP to influence route selection using the local preference attribute

BGP Multi-Exit-Discriminator (MED)

Given a customer scenario where multiple connections must be supported, successfully configure BGP to influence route selection using the Multi-Exit-Discriminator (MED) attribute

BGP Communities

Given a customer scenario where multiple connections must be supported, successfully configure BGP to influence route selection using BGP community attributes

Customer-to-Provider Connectivity with BGP

Customer Connectivity Requirements

Describe the requirements to connect customer networks to the Internet in a service provider environment

Static Routing Toward the Customer

Given a service provider network, implement customer connectivity using static routing

BGP Customer Multi-Homed to a Single Service Provider

Given a customer scenario where multiple connections to a single ISP must be supported, implement customer connectivity with BGP

BGP Customer Multi-Homed to Multiple Service Providers

Given a customer scenario where connections to multiple ISPs must be supported, implement customer connectivity with BGP

BGP Transit Autonomous System

Transit Autonomous System Functions

• Describe the function of a transit autonomous system and the need for IBGP IBGP and EBGP Interaction in a Transit AS
• Given a transit autonomous system, describe the interaction between EBGP and IBGP in relation to relevant BGP attributes

Packet Forwarding in Transit Autonomous Systems

Describe the function of an IGP in forwarding packets through an autonomous system

Configuring a Transit Autonomous System

Given a BGP network scenario, successfully configure an autonomous system to act as a transit backbone

Monitoring and Troubleshooting IBGP in Transit AS

Given a configured BGP transit network, verify proper operation and perform the steps necessary to correct basic IBGP configuration errors

BGP RouteReflectors

Introduction to Route Reflectors

Describe the function and operation of route reflectors in a BGP environment

Network Design with Route Reflectors

Based upon established route reflector design rules, describe the concept of hierarchial route reflectors and their requirements

Configuring and Monitoring Route Reflectors

Given an existing IBGP network, configure and verify proper operation of route reflectors to modify IBGGP split-horizon rules

Advanced BGP Configuration

• Limiting the Number of Prefixes Received from a BGP Neighbor
• Given a typical BGP network, successfully configure BGP to limit the number of prefixes received from a neighbor

AS-Path Prepending

Given a typical service provider network with connections to multiple autonomous systems, use AS-Path prepending to influence the return path selected by the neighboring autonomous systems

BGP Peer Group

Given a typical BGP network, use BGP peer groups to share common configuration parameters between multiple BGP peers

BGP RouteFlap Dampening

Given a properly configured BGP network, use route flap dampening to minimize the impact of unstable routes

Scaling IGP and BGP in Service Provider Networks

Common Routing Issues in Service Provider Networks

Describe common routing concerns of service provider networks

Optical Networking Designs

Describe the scalability issues of using OSPF and IS-IS as interior gateway protocols in a service provider network and list solutions for each

Scaling BGP in Service Provider Networks

Describe common scalability issues when using BGP in a service provider network and list solutions for each