Border Gateway Protocol (BGP) is the routing protocol used to exchange routing information across the Internet. It makes it possible for ISPs to connect to each other and for end-users to connect to more than one ISP. BGP is the only protocol that is designed to deal with a network of the Internet's size, and the only protocol that can deal well with having multiple connections to unrelated routing domains.This book is a guide to all aspects of BGP: the protocol, its configuration and operation in an Internet environment, and how to troubleshooting it. The book also describes how to secure BGP, and how BGP can be used as a tool in combating Distributed Denial of Service (DDoS) attacks. Although the examples throughout this book are for Cisco routers, the techniques discussed can be applied to any BGP-capable router.The topics include:
Requesting an AS number and IP addresses
Route filtering by remote ISPs and how to avoid this
Configuring the initial BGP setup
Balancing the available incoming or outgoing traffic over the available connections
Securing and troubleshooting BGP
BGP in larger networks: interaction with internal routing protocols, scalability issues
BGP in Internet Service Provider networks
The book is filled with numerous configuration examples with more complex case studies at the end of the book to strengthen your understanding. BGP is for anyone interested in creating reliable connectivity to the Internet.
Chapter 1 The Internet, Routing, and BGP
Topology of the Internet
TCP/IP Design Philosophy
Routing Protocols
Multihoming
Chapter 2 IP Addressing and the BGP Protocol
IP Addresses
Interdomain Routing History
The BGP Protocol
Multiprotocol BGP
Interior Routing Protocols
Chapter 3 Physical Design Considerations
Availability
Selecting ISPs
Bandwidth
Router Hardware
Failure Risks
Building a Wide Area Network
Network Topology Design
Chapter 4 IP Address Space and AS Numbers
The Different Types of Address Space
Requesting Address Space
Renumbering IP Addresses
The AS Number
Routing Registries
Routing Policy Specification Language
Chapter 5 Getting Started with BGP
Enabling BGP
Monitoring BGP
Clearing BGP Sessions
Filtering Routes
Internal BGP
The Internal Network
Minimizing the Impact of Link Failures
eBGP Multihop
Chapter 6 Traffic Engineering
Knowing Which Route Is Best
Route Maps
Setting the Local Preference
Manipulating Inbound AS Paths
Inbound Communities
BGP Load Balancing
Traffic Engineering for Incoming Traffic
Setting the MED
Announcing More Specific Routes
Queuing, Traffic Shaping, and Policing
Chapter 7 Security and Integrity of the Network
Passwords and Security
Software
Protecting BGP
Denial-of-Service Attacks
Chapter 8 Day-to-Day Operation of the Network
The Network Operations Center
NOC Hardware Facilities
SNMP Management
Router Names
General IP Network Management
Chapter 9 When Things Start to Go Down: Troubleshooting
Iljitsch van Beijnum has been working with BGP in ISP and end-user networks since 1996. He has configured the protocol on single-router networks; networks with several hundred Ciscos ranging from the slowest to the fastest available; and multivendor environments with BGP running on Cisco and Juniper routers, Extreme switches, and FreeBSD hosts running GNU Zebra
Our look is the result of reader comments, our own experimentation, and feedback from distribution channels. Distinctive covers complement our distinctive approach to technical topics, breathing personality and life into potentially dry subjects. The animal on the cover of BGP is the slender-horned gazelle (Gazella leptoceros). It is the palest of all gazelles and has slightly enlarged hooves for walking on sand. Both sexes have horns: in males, they are about a foot long, slender, and slightly "S" shaped. In females, they are significantly smaller and slimmer, about 8 inches long.Females and young live in groups of 10 to 30. Adult males establish territories late in the year and mate with females that enter these territories. Females give birth in May or June and wean their one offspring approximately three months later. Gazelles weigh approximately 60 pounds and live about 14 years.Due to the extreme heat of its desert environment, the slender-horned gazelle feeds mostly at night and in the early morning. Their water needs are small; morning dew on the vegetation they eat suffices. Their main cooling mechanisms are a reflective white coat and a specially adapted nasal passage.The slender-horned gazelle lives in isolated pockets throughout the central Sahara Desert and has been classified as endangered because of excessive hunting for the animal's meat and horns. Mary Anne Weeks Mayo was the production editor, and Leanne Soylemez was the copyeditor, for BGP. Tatiana Apandi Diaz and Jane Ellin provided quality control. Phil Dangler provided production assistance. Lynda D'Arcangelo wrote the index.Ellie Volckhausen designed the cover of this book, based on a series design by Edie Freedman. The cover image is an original antique engraving. Emma Colby produced the cover layout with QuarkXPress 4.1 using Adobe's ITC Garamond font.David Futato designed the interior layout. This book was converted to FrameMaker 5.5.6 by Joe Wizda with a format conversion tool created by Erik Ray, Jason McIntosh, Neil Walls, and Mike Sierra that uses Perl and XML technologies. The text font is Linotype Birka; the heading font is Adobe Myriad Condensed; and the code font is LucasFont's TheSans Mono Condensed. The illustrations that appear in the book were produced by Robert Romano and Jessamyn Read using Macromedia FreeHand 9 and Adobe Photoshop 6. The tip and warning icons were drawn by Christopher Bing. This colophon was compiled by Mary Anne Weeks Mayo.
