Posts Tagged ‘bgp convergence’

Mar
21

The CCDE bootcamp is coming shortly on May 1st, and we would like to provide some information to those of you who have already registered for the class or considering to join us. The class will go for five days and finish right before the CCDE practical exam in Chicago. The class is interactive for the most part – instructor will present you documents, diagrams, slides and questions on board and then the whole class will go through the solutions in live mode, discussing various options and correct answers. The class is centered around three major “platforms”: generic “large-scale” network topologies that are used to construct various network design cases. There are three main platforms presented in the class:

  • Internet Service Provider. A fictitious ISP that provides VPN and Internet services to enterprises in addition to wholesale Internet services. Generic two-layer network, featuring a mix of interconnection technologies and using ISIS/BGP for routing. This platform is mainly used to work with scenarios relating to transit traffic services.
  • Application Service Provider. A company that has its own wide-area network interconnecting data-centers and points-of-presence. The company provides server application services – e.g. a virtual call-center, online support desk etc to multiple customers. Customers connect either directly or tunneling over Internet. This platform is used to demonstrate issues arising in networks that provide centralized services to different customers. This network uses OSPF and BGP for routing, traffic flows are mainly considered to be “client-server” flows between different networks.
  • Large Enterprise Network. Presents a generic enterprise network with diverse set of offices and private WAN network. The network services just one company, but has to support a large variety of application and different connection types. Traffic flows are mainly contained to one network but there are multiple “concentration” points. The network uses EIGRP for routing.

Every platform is used to construct 5 different scenarios, featuring from 15 to 20 different questions each. Answering each question requires analyzing the network baseline and additional information presented through the course of the class and selecting the optimal answer. Similar to the actual exam, the scenarios will have one the the following logical structures:

  • Merge two networks or spin off a new network.
  • Add a service or application – e.g. deploy L3 VPNs or add VoIP.
  • Scale the network – accommodate technologies to network growth, e.g. IGP/BGP/MPLS scaling.
  • Replace a technology – e.g. replace routing protocol or link type with another one.

You will be required to do a “fresh” design or fix a faulty/suboptimal scenario and propose a better solution. For example, you may be asked to fix a network that has new application deployed that is not working as required. The class will focus on live discussion of design problems as well as strategy tips for passing the CCDE practical exam. One again, students are assumed to have knowledge equivalent in scope to CCIE Written exam blueprint. And lastly, the following is link to a sample CCDE scenario – baseline and questions in the format they are going to be presented during the class.

Tags: , , ,

Nov
22

Introduction

BGP (see [0]) is the de-facto protocol used for Inter-AS connectivity nowadays. Even though it is commonly accepted that BGP protocol design is far from being ideal and there have been attempts to develop a better replacement for BGP, none of them has been successful. To further add to BGP’s widespread adoption, MP-BGP extension allows BGP transporting almost any kind of control-plane information, e.g. to providing auto-discovery functions or control-plane interworking for MPLS/BGP VPNs. However, despite BGP’s success, the problems with the protocol design did not disappear. One of them is slow convergence, which is a serious limiting factor for many modern applications. In this publication, we are going to discuss some techniques that could be used to improve BGP convergence for Intra-AS deployments.

BGP-Only Convergence Process
Tuning BGP Transport
BGP Fast Peering Session Deactivation
BGP and IGP Interaction
BGP PIC and Multiple-Path Propagation
Practical Scenario: BGP PIC + BGP NHT
Considerations for Implementing BGP PIC
Summary
Further Reading
Appendix: Practical Scenario Baseline Configuration
Continue Reading

Tags: , , , , , ,

Categories

CCIE Bloggers