--- 1/draft-ietf-grow-simple-va-10.txt 2012-08-01 01:14:03.833342524 +0200 +++ 2/draft-ietf-grow-simple-va-11.txt 2012-08-01 01:14:03.849343092 +0200 @@ -1,88 +1,92 @@ + GROW Working Group R. Raszuk Internet-Draft NTT MCL Intended status: Informational J. Heitz -Expires: January 6, 2013 Ericsson +Expires: January 2, 2013 Ericsson A. Lo Arista L. Zhang UCLA X. Xu Huawei - July 5, 2012 + July 2012 Simple Virtual Aggregation (S-VA) - draft-ietf-grow-simple-va-10.txt + draft-ietf-grow-simple-va-11.txt Abstract All BGP routers in the Default Free Zone (DFZ) are required to carry all the routes in the Default Free Routing Table (DFRT). A technique is described that allows some BGP routers not to install all of those routes into the Forwarding Information Base (FIB). Some routers in an Autonomous System (AS) announce an aggregate (the VA prefix) in addition to the routes they already announce. This enables other routers not to install the routes covered by the VA prefix into the FIB as long as those routes have the same next-hop as the VA prefix. The VA prefixes that are announced within an AS are not announced to - any other AS. + any other AS. In contrast to VA, S-VA reduces operational complexity + by proposing local to given BGP speaker solution without any + dependency on network wide configuration or requires presence of any + form of intra-domain tunneling. Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on January 6, 2013. + This Internet-Draft will expire on January 2, 2013. Copyright Notice Copyright (c) 2012 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents - 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 1.1. Scope of this Document . . . . . . . . . . . . . . . . . . 3 - 1.2. Requirements notation . . . . . . . . . . . . . . . . . . . 3 - 1.3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3 - 2. Operation of S-VA . . . . . . . . . . . . . . . . . . . . . . . 4 - 3. Deployment considerations . . . . . . . . . . . . . . . . . . . 6 - 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 - 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 7 - 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7 - 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 - 7.1. Normative References . . . . . . . . . . . . . . . . . . . 7 - 7.2. Informative References . . . . . . . . . . . . . . . . . . 7 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 7 + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 + 1.1. Scope of this Document . . . . . . . . . . . . . . . . . . 4 + 1.2. Requirements notation . . . . . . . . . . . . . . . . . . . 4 + 1.3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 4 + 2. Operation of S-VA . . . . . . . . . . . . . . . . . . . . . . . 5 + 3. Deployment considerations . . . . . . . . . . . . . . . . . . . 7 + 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7 + 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 8 + 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 8 + 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8 + 7.1. Normative References . . . . . . . . . . . . . . . . . . . 8 + 7.2. Informative References . . . . . . . . . . . . . . . . . . 8 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8 1. Introduction A technique called Simple Virtual Aggregation (S-VA) is described. It allows some routers not to have to store some routes in the Forwarding Information Base (FIB) while still advertising and receiving the full Default Free Routing Table (DFRT) in BGP. A typical scenario is as follows. Core routers in the ISP maintain the full DFRT in the FIB and RIB. Edge routers maintain the full @@ -125,21 +129,21 @@ Suppress: Not to install a route that is covered by the VA-prefix into the global RIB or FIB Legacy Router: A router that does not run S-VA, and has no knowledge of S-VA. Global Routing Information Base (RIB): All the routing protocols in a router install their selected routes into the RIB. The routes in the RIB are used to resolve next-hops for other routes, to be redistributed to other routing protocols and to be installed into the FIB. - Local/Protocol Routing Information Base (loc-RIB): The Loc-RIB + Local/Protocol Routing Information Base (Loc-RIB): The Loc-RIB contains the routes that have been selected by the local BGP speaker's Decision Process as in [RFC4271]. NLRI: Network Layer Reachability Information [RFC4271] 2. Operation of S-VA There are three types of routers in S-VA, FIB-Installing routers (FIR), FIB-Suppressing routers (FSR) and optionally, legacy routers. While any router can be an FIR or an FSR, the simplest form of deployment is for AS border routers to be configured as FIRs and for @@ -231,21 +235,21 @@ reachability of any destination, a router can be configured not to resolve next-hops using the default route. In this case, S-VA should not suppress from installation into the RIB a route that may be used to resolve a next-hop for another route. It may still suppress it from installation into the FIB Selected BGP routes in the RIB may be redistributed to other protocols. If they no longer exist in the RIB, they will not be redistributed. This is especially important when the conditional redistribution is taking place based on the length of the prefix, - community value etc .. In those cases where redistribution policy is + community value etc. In those cases where redistribution policy is in place S-VA code should refrain from suppressing from installation into the RIB routes matching such policy. It may still suppress them from installation into the FIB. A router may originate a network route or an aggregate route into BGP. Some addresses covered by such a route may not exist. If this router were to receive a packet for an unreachable address within an originated route, it must not send that packet to the VA-prefix route. There are several ways to achieve this. One is to have the FIR aggregate the routes instead of the FSR. Another is to install a