Open Shortest Path First IGP S. Hegde
Internet-Draft P. Sarkar
Intended status: Standards Track H. Gredler
Expires: January 17, 2016 Juniper Networks, Inc.
M. Nanduri
Microsoft Corporation
L. Jalil
Verizon
July 16, 2015

OSPF Link Overload
draft-hegde-ospf-link-overload-01

Abstract

Many OSPFv2 or OSPFv3 deployments run on overlay networks provisioned by means of pseudo-wires or L2-circuits. when the devices in the underlying network go for maintenance, it is useful to divert the traffic away from the node before the maintenance is actually scheduled. Since the nodes in the underlying network are not visible to OSPF, existing stub router mechanism described in [RFC3137] cannot be used. It is useful for routers in OSPFv2 or OSPFv3 routing domain to be able to advertise a link being in overload state to indicate impending maintenance activity in the underlying network devices.

This document describes the protocol extensions to disseminate link overload information in OSPFv2 and OSPFv3 protocol.

Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].

Status of This Memo

This Internet-Draft is submitted 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/.

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This Internet-Draft will expire on January 17, 2016.

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Table of Contents

1. Introduction

It is useful for routers in OSPFv2 or OSPFv3 routing domain to be able to advertise a link being in overload state to indicate impending maintenance activity on the link. This document provides mechanisms to advertise link overload state in the flexible encodings provided by OSPFv2 Prefix/Link Attribute Advertisement( [I-D.ietf-ospf-prefix-link-attr]) and OSPFv3 Extended LSA ([I-D.ietf-ospf-ospfv3-lsa-extend]). Throughout this document, OSPF is used when the text applies to both OSPFv2 and OSPFv3. OSPFv2 or OSPFv3 is used when the text is specific to one version of the OSPF protocol.

2. Link overload sub TLV

2.1. OSPFv2 Link overload sub TLV