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Using a Dedicated AS for Sites Homed to a Single Provider (RFC2270)

IP.com Disclosure Number: IPCOM000002831D
Original Publication Date: 1998-Jan-01
Included in the Prior Art Database: 2019-Feb-15
Document File: 6 page(s) / 8K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

J. Stewart: AUTHOR [+3]

Related Documents

10.17487/RFC2270: DOI

Abstract

With the increased growth of the Internet, the number of customers using BGP4 has grown significantly. RFC1930 outlines a set of guidelines for when one needs and should use an AS. However, the customer and service provider (ISP) are left with a problem as a result of this in that while there is no need for an allocated AS under the guidelines, certain conditions make the use of BGP4 a very pragmatic and perhaps only way to connect a customer homed to a single ISP. This paper proposes a solution to this problem in line with recommendations set forth in RFC1930. This memo provides information for the Internet community. It does not specify an Internet standard of any kind.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 34% of the total text.

Network Working Group J. Stewart Request for Comments: 2270 ISI Category: Informational T. Bates R. Chandra E. Chen Cisco January 1998

Using a Dedicated AS for Sites Homed to a Single Provider

Status of this Memo

This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited.

Copyright Notice

Copyright (C) The Internet Society (1998). All Rights Reserved.

Abstract

With the increased growth of the Internet, the number of customers using BGP4 has grown significantly. RFC1930 outlines a set of guidelines for when one needs and should use an AS. However, the customer and service provider (ISP) are left with a problem as a result of this in that while there is no need for an allocated AS under the guidelines, certain conditions make the use of BGP4 a very pragmatic and perhaps only way to connect a customer homed to a single ISP. This paper proposes a solution to this problem in line with recommendations set forth in RFC1930.

1. Problems

With the increased growth of the Internet, the number of customers using BGP4 [1],[2] has grown significantly. RFC1930 [4] outlines a set of guidelines for when one needs and should use an AS. However, the customer and service provider (ISP) are left with a problem as a result of this in that while there is no need for an allocated AS under the guidelines, certain conditions make the use of BGP4 a very pragmatic and perhaps only way to connect a customer homed to a single ISP. These conditions are as follows:

1) Customers multi-homed to single provider

Stewart, et. al. Informational [Page 1]

RFC 2270 Dedicated AS January 1998

Consider the scenario outlined in Figure 1 below.

+-------+ +-------+ +----+ | | | +------+ | | ISP A +------+ ISP B | | Cust.+---+ | | | | | X +--------+ | | | +------+ ++-----++\ +-------+ | | \ | | \ +--------+ ++-----++ +-| | | Cust. | | ISP C | | Y | | | +-------+ +--------+

Figure 1: Customers multi-home to a single provider

Here both customer X and customer Y are multi-homed to a single provider, ISP A. Because these multiple connections are "localized" between the ISP A and its customers, the rest of the routing system (ISP B and ISP C in this case) doesn’t need to see routing information for a single multi-homed customer any differently than a singly-homed customer as it has the same routing policy as ISP A relative to ISP B and ISP C. In other words, with respect to the rest of the Internet routing system the organization is singly-homed, so the complexity of the multiple connections is not relevant in a global sense. Autonomous System Numbers (AS) are identifiers used in routing protocols and are needed by routing domains as part of the global routing system. However, as [4] correctly outlines, organizations with the same routing policy as their upstream provider do not need an AS.

Despite this fact, a problem exists in that many ISPs can only support the load-sharing and reliability requiremen...

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