Cisco BGP Video Guide to Configuration and Deployment

Border Gateway Protocol (BGP) has been around for over a decade, and has been considered to be one of the most stable, scalable and feature-rich routing protocols. What used to once be a routing protocol that was primarily used to build the internet and in service provider realm, it has pervasively made its way into enterprise networks. 

 

Today, BGP is the main routing protocol used by many companies to interface with their ISP and MPLS provider. This usually requires network administrators to only have basic knowledge of BGP that is enough to get the connection up and running, and possibly for day-to-day troubleshooting. However, if you wish to get the most out of the protocol in terms of routing control, security, or scalability especially if you plan for BGP internal implementation, it is inevitable to spend time and try to understand the protocol and be aware of what BGP has to offer.   

 

Lab Minutes have put together a series of video tutorial to help you, not only learn how to configure BGP on Cisco router, but also understand the underlying technologies and operations so that you are ready to deploy BGP in your network. The topics that will be covered extend from fundamental of BGP and commonly used features, the knowledge that is usually required by network administrators to manage their production network, to the more advance features for those who are studying for Cisco certifications.

 

This article will guide you through BGP videos that are available on our website, either as free online steaming or video download, and provide overview of how to best utilize these video to maximize your learning experience. For more information on the technology, please consult Cisco documentation.

 

BGP Fundamental

As with many other routing protocols, route exchange cannot happen without a neighbor adjacency being formed. So the first video is all about configuring BGP neighbors and understanding the differences between two types of BGP; iBGP and eBGP.

Once the routers have neighbor adjacencies, routes can be exchanged. This video demonstrates different ways to introduce routes into the network and the behavior of route advertisement within and across Autonomous System (AS) to achieve basic connectivity.

Routing Policy and Control

The highlight of BGP is the ability to have complete control on route advertisement, and how traffic will be routed within, inbound, or outbound of your network. The next few videos walk you through some of the tools that you have at your disposal to accomplish this.

Advance route advertisement videos take you through the concept of conditional route advertisement, and that is how to advertise routes based on existence or non-existence of another route. Although this might be less applicable in real-life, there could be a specialized circumstance that call for this feature.

Route filter is a tool used to control which routes you want the external network to see and which routes you want to see to dictate network reachability. Route filter seems common in all routing protocols but with BGP, you are not limited to prefix-based route filter. BGP allows various BGP attributes, including community values, to be matched under a route-map, not to mention Regular Expression (RegEx) matching that is also available. These videos will show different ways of implementing a route filter (Prefix-List, filter-List, Route-Map), including a more advance feature like Outbound Route Filter (ORF).

Path Selection is probably one of the most important concepts to grasp when learning BGP. BGP chooses the best path, which is consequently installed to the router routing table, based on the priority of route attributes. It is very important to get to know these attributes in order to predict BGP routing behavior. The following videos take you through the list of attribute from the lowest to the highest priority with accompanying lab scenarios and emphasis on some attributes that you can expect to encounter in the real world. 

Scalability

The main reason that BGP is the primary building block of the internet is its scalability. The next few videos offer guidance into some BGP features that you can adopt to build a scalable network.

Route summarization is also another concept that exists with other routing protocols. However, BGP takes it to next level with its complexity and required consideration for the attributes involved. BGP route summarization allows routes to be fully or selectively summarized, BGP attributes to be manipulated, have only certain routes be included or excluded from summarization, or even undoing a summarized route, and all these are covered in the following videos.

Being able to minimize the amount of configuration required on a router also contributes to scalability of a network. This video shows how to streamline BGP configuration using traditional Peer Group and a more efficient method of Peer Template. As an unrelated side discussion, we will also be covering BGP configuration of IPv4 VRF. 

The next two sets of videos presents the two most popular methods of building a highly scalable iBGP network. As you may know by now, iBGP inherently requires all participating routers to have BGP sessions in a full-mesh topology, which is a severe limitation. Route Reflector and Confederation offer alternative solutions by altering the default behavior of iBGP. In the following videos, you will learn what you need to know about these two technologies, their similarities and differences, and the new rules of iBGP route advertisement.

        Route Reflector

        Confederation

Advance Features

This section contains videos of miscellaneous features and some of the features that are more likely to be found when study for certifications.

BGP has a built-in mechanism to detect and suppress flapping routes to increase network stability, and this is known as route dampening. These videos will first talk about some terminologies you need to familiarize yourself with before taking you to see the feature in action.

BGP supports various address-family in addition to IPV4 unicast. What this means is you will be able to have multiple independent BGP topology, one per address-family. The following videos specifically cover how to configure BGP routing for multicast traffic when the topology needs to differ from the unicast routing.

By default, eBGP only works when peers are directly connected. Since a BGP session relies on TCP, it is certainly possible for a BGP session to work across multiple L3 hops. The following videos show you how to accomplish this with two alternatives. Pros and cons for each method will be discussed and why you may want to implement one over the other.

The following videos present you with less common scenarios to manipulate an AS number in a route AS-path to allow routes to be accepted in a certain AS. We will also talk about how to secure a BGP session with peer authentication.

This is another feature that is uncommon and only included here for certification study. You might be familiar with configuring class-map and policy-map to perform QoS classification with matching performed base on an ACL or traffic protocol. QPPB on the other hand, allows traffic to be classified and marked based on BGP route attributes and this is what will be discussed in this video.

IPv6

For completeness of this video guide, we will conclude with BGP implementation for IPv6. Although these videos will not go into detail or cover the same set of features, they will provide you with enough information to get you started. Once you pass the basic setup, the same knowledge that you have accumulated throughout this guide on IPv4 BGP, for the most part, immediately apply to IPv6 BGP. 

So hopefully these tutorial videos have provided enough working knowledge on BGP for you to comfortably operate a BGP-enabled network, and even incorporate it into your next network design. For those that are pursuing Cisco certification, we hope that you have benefited as much and got better insight of the technology. If you have any question, feel free to post them under the corresponding video page or Lab Minutes forum.