tailieunhanh - BGP-Case-Studies

The Border Gateway Protocol (BGP), defined in RFC 1771, allows you to create loop free interdomain routing between autonomous systems. An autonomous system is a set of routers under a single technical administration. Routers in an AS can use multiple interior gateway protocols to exchange routing information inside the AS and an exterior gateway protocol to route packets outside the AS. | BGP4 Case Studies Tutorial Sam Halabi-cisco Systems The purpose of this paper is to introduce the reader to the latest in BGP4 terminology and design issues. It is targeted to the novice as well as the experienced user. For any clarification or comments please send e-mail to shalabi@. Copyright 1995 Cisco Systems Inc. 1 26 96-Rev Page 1 Sam Halabi-cisco Systems I. 0 How does BGP What are peers neighbors .4 Information exchange between EBGP and Enabling BGP BGP Neighbors BGP and Loopback EBGP EBGP Multihop Load Balancing .12 Route Network Static routes and Internal The BGP decision As_path II. 0 Origin BGP Nexthop BGP Nexthop Multiaccess Networks .29 BGP Nexthop NBMA .30 BGP Disabling Weight Local Preference Metric Attribute .41 Community BGP Route Path AS-Regular BGP Community BGP Neighbors and Route Use of set as-path BGP Peer CIDR and Aggregate Addresses .58 1 26 96-Rev Page 2 Sam Halabi-cisco Systems Aggregate CIDR example CIDR example 2 as-set .63 BGP Route Multiple RRs within a RR and conventional BGP Avoiding looping of routing Route Flap How BGP selects a Practical design example .80 1 26 96-Rev Page 3 Sam Halabi-cisco .