Browse Prior Art Database

Scalable Support for Multi-homed Multi-provider Connectivity (RFC2260)

IP.com Disclosure Number: IPCOM000002820D
Original Publication Date: 1998-Jan-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 10 page(s) / 26K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

T. Bates: AUTHOR [+2]

Abstract

This document describes addressing and routing strategies for multi- homed enterprises attached to multiple Internet Service Providers (ISPs) that are intended to reduce the routing overhead due to these enterprises in the global Internet routing system.

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 11% of the total text.

Network Working Group T. Bates

Request for Comments: 2260 Cisco Systems

Category: Informational Y. Rekhter

Cisco Systems

January 1998

Scalable Support for Multi-homed Multi-provider Connectivity

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.

2. Abstract

This document describes addressing and routing strategies for multi-

homed enterprises attached to multiple Internet Service Providers

(ISPs) that are intended to reduce the routing overhead due to these

enterprises in the global Internet routing system.

3. Motivations

An enterprise may acquire its Internet connectivity from more than

one Internet Service Provider (ISP) for some of the following

reasons. Maintaining connectivity via more than one ISP could be

viewed as a way to make connectivity to the Internet more reliable.

This way when connectivity through one of the ISPs fails,

connectivity via the other ISP(s) would enable the enterprise to

preserve its connectivity to the Internet. In addition to providing

more reliable connectivity, maintaining connectivity via more than

one ISP could also allow the enterprise to distribute load among

multiple connections. For enterprises that span wide geographical

area this could also enable better (more optimal) routing.

The above considerations, combined with the decreasing prices for the

Internet connectivity, motivate more and more enterprises to become

multi-homed to multiple ISPs. At the same time, the routing overhead

that such enterprises impose on the Internet routing system becomes

more and more significant. Scaling the Internet, and being able to

support a growing number of such enterprises demands mechanism(s) to

contain this overhead. This document assumes that an approach where

routers in the "default-free" zone of the Internet would be required

to maintain a route for every multi-homed enterprise that is

connected to multiple ISPs does not provide an adequate scaling.

Moreover, given the nature of the Internet, this document assumes

that any approach to handle routing for such enterprises should

minimize the amount of coordination among ISPs, and especially the

ISPs that are not directly connected to these enterprises.

There is a difference of opinions on whether the driving factors

behind multi-homing to multiple ISPs could be adequately addressed by

multi-homing just to a single ISP, which would in turn eliminate the

negative impact of multi-homing on the Internet routing system.

Discussion of this topic is beyond the scope of this ...