Routing Protocols Conﬁguration Guide

Tellabs 8600 Smart RoutersRouting Protocols Configuration Guide

76.8600-50121F13.01.2014

Document Information

Revision History

Document No. Date Description of Changes

76.8600-50121F 13.01.2014 Renewed related documentation table in Tellabs 8600 SmartRouters Technical Documentation.Added ECMP support in ELC1 line card in 9 Equal Cost Multipath(ECMP).Added 3.9 BGP Failover.Added support of BFD for single hop BGP in 7 BidirectionalForwarding Detection .Updates applied in 6.1 IS-IS Basic Configuration.Added a configuration example of 8.1.4 Single Hop BGP.Added clarification of VRRP multiple instances configuration toan interface in 10.2.1 VRRP Parameters.Added ELC1 support of VRRP + IRB and VRRP + ELP in10.3.1 Implementation.VRRP master and backup roles corrected in 11.1.2 Router2Configuration.Updates and corrections applied in 8.2 BFD Configuration forStatic Routes.Changes applied in 3.2 BGP Attributes and reworked3.2.6 COMMUNITY Attribute.

76.8600-50121E 28.08.2012 New Tellabs 8600 brand: Tellabs 8600 managed edge system andTellabs 8600 network elements changed to Tellabs 8600 smartrouters.Related documentation table updated.Major changes and updates applied to BGP section 3 BorderGateway Protocol : Added BGP attributes 3.2 BGP Attributes.

Route policing updates 3.4 BGP Routing Policy .

Renewed 3.5 Route Aggregation and added route aggregationfor VPNs 3.5.2 BGP VPN Route Aggregation.

Renewed RFD and graceful restart in .

Renewed 3.7 Route Refresh.

Renewed 3.8.1 Route Reflector and 3.8.2 AS Confederation.

BGP configuration updates and CLI examples layout change fromtable to step list in 4 BGP Configuration Examples: Updates in 4.1 Basic Configurations.

Added route aggregation for VPNs configuration in 4.2 RouteAggregation Configuration.

Renewed RR and AS confederation configuration examples in4.3 Advanced Configurations .

Corrections made to 7 Bidirectional Forwarding Detection .Updates in 9 Equal Cost Multipath (ECMP) and ECMP9.3.4 Scalability.VRRP support in ELC1 10.3.1 Implementation.CLI examples layout change from table format to step listin: 2 OSPF Configuration Examples; 6 IS-IS ConfigurationExamples; 8 BFD Configuration Examples and 11 VRRP CLIConfiguration Examples.

Tellabs 8600 Smart Routers 76.8600-50121FRouting Protocols Configuration Guide 2014 Tellabs.

2

Document No. Date Description of Changes

76.8600-50121D 02.11.2011 Updated VRRP parameters in 10.2.1 VRRP Parameters.Added VRRP timers, starting conditions and initial timer values ofa VRRP backup router in 10.2.2 VRRP Timers.Added tracking delay timer in 10.3.2 Object Tracking.

76.8600-50121C 27.09.2011 BGP overview updates (introduction, BGP peering, managingroute preferences, next-hop attribute and BGP routing policy) in3 Border Gateway Protocol .Updated BGP basic configuration examples in 4.1 BasicConfigurations.Added precautions of avoiding packet loss in VRRP aftermastership role switchover in 10.3.2 Object Tracking.Added a setup of waiting time after VRRP initialization beforemastership role switchover to prevent unnecessary switchover in10.3.3 VRRP with IRB.Added configuration step of setting the waiting time after VRRPinitialization in 11.2 VRRP with IRB Configuration.

76.8600-50121B 25.08.2011 BFD monitoring for static routes 7 Bidirectional ForwardingDetection . BFD configuration in static routing 8.2 BFDConfiguration for Static Routes. BFD session information8.2.1 BFD Status.Virtual Router Redundancy Protocol 10 Virtual RouterRedundancy Protocol. VRRP Configuration 11 VRRP CLIConfiguration Examples.ECMP routing 9 Equal Cost Multipath (ECMP).OSPF status and statistics 2.10 OSPF Status .BGP overview in 3 Border Gateway Protocol and BGP peeringTCP session. BGP next-hop area support 3.2.3 NEXT HOPAttribute. BGP Policing using communities attribute androute-map in 3.4 BGP Routing Policy .Renewed BGP basic configuration (also added BGP configurationstatus); added BGP routing policy configuration examples andupdates in BGP authentication, connection reset 4.1 BasicConfigurations. BGP advanced configuration changed ASnumbers.

This revision of the manual documents the following network elements and the correspondingfeature packs or higher.

Tellabs 8605 smart router FP1.6

Tellabs 8607 smart router FP1.1

Tellabs 8609 smart router, Tellabs 8611 smart router FP1.2

Tellabs 8620 smart router, Tellabs 8630 smart router, Tellabs 8660 smart router FP4.1

If you have a different feature pack of Tellabs 8600 products, please refer to the relevant productdocument program on the Tellabs Portal by navigating to www.portal.tellabs.com > ProductDocumentation > Data Networking > Tellabs 8600 Smart Routers > Technical Documentation.

2014 Tellabs. All rights reserved.

This Tellabs manual is owned by Tellabs or its licensors and protected by U.S. and international copyright laws, conventions andtreaties. Your right to use this manual is subject to limitations and restrictions imposed by applicable licenses and copyright laws.Unauthorized reproduction, modification, distribution, display or other use of this manual may result in criminal and civil penalties.The following trademarks and service marks are owned by Tellabs Operations, Inc. or its affiliates in the United States and/or

other countries: TELLABS, TELLABS logo, TELLABS and T symbol, and T symbol.

Any other company or product names may be trademarks of their respective companies.

The specifications and information regarding the products in this manual are subject to change without notice. All statements,information, and recommendations in this manual are believed to be accurate but are presented without warranty of any kind,

express or implied. Users must take full responsibility for their application of any products.

Adobe Reader are registered trademarks of Adobe Systems Incorporated in the United States and/or other countries.


4


Terms and Abbreviations

Term Explanation

ABR Area Border Router

AFI Authority and Format Identifier

ARP Address Resolution Protocol

AS Autonomous System

ASBR Autonomous System Border Router

BFD Bidirectional Forwarding Detection

BGP Border Gateway Protocol

CDC Control and DC Power Card

CLI Command Line Interface

CPU Central Processing Unit

CSPF Constrained Shortest Path First

DCN Data Communications Network

DD Database Description

DiffServ Differentiated Services

DR Designated Router

eBGP External Border Gateway Protocol

ECMP Equal Cost Multipath

EGP Exterior Gateway Protocol

ELP Ethernet Layer Protection

ES-IS End System to Intermediate System

iBGP Internal Border Gateway Protocol

ICMP Internet Control Message Protocol

IFC Interface Module Concentrator

IFM Interface Module

IGP Interior Gateway Protocol

IIH IS-IS Hello

IP Internet Protocol

IRB Integrated Routing and Bridging

IS-IS Intermediate System to Intermediate System

LAG Link Aggregation

LAN Local Area Network

LDP Label Distribution Protocol

LSA Link-State Advertisement

76.8600-50121F Tellabs 8600 Smart Routers 2014 Tellabs. Routing Protocols Configuration Guide

5


LSP Label Switched Path

LSP Link State Packet

MAC Media Access Control

MDA Message Digest Authentication

MED Multi Exit Discriminator

MPLS Multiprotocol Label Switching

NBMA Non-Broadcast Multiaccess

NET Network Entity Title

NSAP Network Service Access Point

NSEL NSAP selector

NSSA Not-So-Stubby Area

ORF Outbound Route Filter

OSPF Open Shortest Path First

QoS Quality of Service

RFC Request For Comments (IETF documents)

RFD Route Flap Damping

RR Route Reflector

RSVP-TE Resource Reservation Protocol with Traffic Engineering Extensions

RT Route Target

SAFI Subsequent Address Family Identifier

SCM Switching and Control Module

SLA Service Level Agreement

SPF Shortest Path First

SOO Site of Origin

TCP Transmission Control Protocol

TE Traffic Engineering

TED Traffic Engineering Database

TLV Type Length Value

VLAN Virtual LAN

VPN Virtual Private Network

VRF Virtual Routing and Forwarding

VRRP Virtual Router Redundancy Protocol


6

Table of Contents

Table of Contents

About This Manual ............................................................................................................ 11

Objectives........................................................................................................................................................................11Audience..........................................................................................................................................................................11Tellabs 8600 Smart Routers Technical Documentation ..................................................................................................11Interface Numbering Conventions ................................................................................................................................. 15Documentation Feedback............................................................................................................................................... 15

Tellabs 8600 Rebranding .................................................................................................. 16

Tellabs 8600 Discontinued Products............................................................................... 17

1 OSPF............................................................................................................................. 19

1.1 Overview ............................................................................................................................................................. 191.2 OSPF Hierarchical Routing ................................................................................................................................ 20

1.2.1 Autonomous System............................................................................................................................ 201.2.2 Areas.................................................................................................................................................... 20

1.3 OSPF Hello Messages and Link-State Advertisements ...................................................................................... 211.4 Extensions for Support of Differentiated Services-Aware MPLS Traffic Engineering....................................... 211.5 OSPF Graceful Restart ........................................................................................................................................ 211.6 Fast OSPF Adjacency Establishment .................................................................................................................. 221.7 OSPF Unnumbered Links.................................................................................................................................... 231.8 OSPF References................................................................................................................................................. 23

2 OSPF Configuration Examples .................................................................................. 24

2.1 Basic Configuration ............................................................................................................................................. 242.2 Interface Configuration........................................................................................................................................ 252.3 Area Configuration .............................................................................................................................................. 252.4 Authentication ..................................................................................................................................................... 262.5 TE Configuration ................................................................................................................................................. 262.6 Graceful Restart Configuration............................................................................................................................ 262.7 Fast OSPF Convergence ...................................................................................................................................... 272.8 Fast OSPF Adjacency Establishment Configuration ........................................................................................... 28

2.8.1 Enabling Hello replies ......................................................................................................................... 28


7

Table of Contents

2.8.2 Designated Router (DR) Wait Time Configuration ............................................................................. 292.9 OSPF Unnumbered Links Configuration ............................................................................................................ 312.10 OSPF Status ........................................................................................................................................................ 32

3 Border Gateway Protocol .......................................................................................... 33

3.1 Overview ............................................................................................................................................................. 333.2 BGP Attributes .................................................................................................................................................... 36

3.2.1 ORIGIN Attribute................................................................................................................................ 373.2.2 AS PATH Attribute .............................................................................................................................. 373.2.3 NEXT HOP Attribute .......................................................................................................................... 383.2.4 LOCAL PREFERENCE Attribute ...................................................................................................... 393.2.5 ATOMIC AGGREGATE Attribute ..................................................................................................... 403.2.6 COMMUNITY Attribute..................................................................................................................... 403.2.7 AGGREGATOR Attribute................................................................................................................... 413.2.8 MED Attribute..................................................................................................................................... 42

3.3 Managing Route Preferences............................................................................................................................... 433.4 BGP Routing Policy ........................................................................................................................................... 44

3.4.1 Route Map ........................................................................................................................................... 453.5 Route Aggregation............................................................................................................................................... 47

3.5.1 Configuration Parameters .................................................................................................................... 493.5.2 BGP VPN Route Aggregation............................................................................................................. 493.5.3 Route Aggregation Support ................................................................................................................. 50

3.6 Route Flap Damping............................................................................................................................................ 503.6.1 RFD Configuration .............................................................................................................................. 52

3.7 Route Refresh ...................................................................................................................................................... 533.8 Increasing AS Scalability .................................................................................................................................... 53

3.8.1 Route Reflector .................................................................................................................................... 533.8.2 AS Confederation ................................................................................................................................ 55

3.9 BGP Failover ....................................................................................................................................................... 563.9.1 iBGP and Multihop eBGP Sessions .................................................................................................... 563.9.2 Single Hop eBGP................................................................................................................................. 573.9.3 Performance of BGP Failover ............................................................................................................. 58

3.10 BGP Multiprotocol Extension ............................................................................................................................. 583.11 BGP References................................................................................................................................................... 59

4 BGP Configuration Examples .................................................................................... 60

4.1 Basic Configurations............................................................................................................................................ 604.1.1 BGP Neighbor and Path ...................................................................................................................... 614.1.2 BGP Routing Policy Configuration ..................................................................................................... 644.1.3 BGP Authentication............................................................................................................................. 664.1.4 BGP Connection Reset ........................................................................................................................ 66

4.2 Route Aggregation Configuration ....................................................................................................................... 674.2.1 NODE-1 Configuration........................................................................................................................ 674.2.2 NODE-2 Configuration........................................................................................................................ 684.2.3 Configuration Status ............................................................................................................................ 684.2.4 Configuration with Suppression Disabled ........................................................................................... 69

4.3 Advanced Configurations ................................................................................................................................... 704.3.1 Route Reflector Configuration............................................................................................................. 70


8

Table of Contents

4.3.2 Configuring AS Confederation ........................................................................................................... 73

5 IS-IS .............................................................................................................................. 77

5.1 Overview ............................................................................................................................................................. 775.2 Routing Areas ...................................................................................................................................................... 785.3 Addressing ........................................................................................................................................................... 795.4 Multihoming ........................................................................................................................................................ 805.5 Multiarea Routing................................................................................................................................................ 805.6 Open Shortest Path Algorithm............................................................................................................................. 815.7 Adjacencies and Hello Packets............................................................................................................................ 815.8 Link-State Database and Link-State Packets ...................................................................................................... 815.9 Route Summarization .......................................................................................................................................... 815.10 Route Redistribution............................................................................................................................................ 825.11 Authentication ..................................................................................................................................................... 825.12 Extensions for Support of Differentiated Services-Aware MPLS Traffic Engineering....................................... 825.13 IS-IS References .................................................................................................................................................. 83

6 IS-IS Configuration Examples .................................................................................... 84

6.1 IS-IS Basic Configuration.................................................................................................................................... 846.1.1 IS-IS Process Configuration ................................................................................................................ 856.1.2 IS-IS Interface Configuration .............................................................................................................. 85

6.2 IS-IS Area Configuration.................................................................................................................................... 866.2.1 Router 1 Configuration ........................................................................................................................ 876.2.2 Router 3 Configuration ........................................................................................................................ 886.2.3 Router 4 Configuration ........................................................................................................................ 88

6.3 Fast IS-IS Convergence ....................................................................................................................................... 89

7 Bidirectional Forwarding Detection .......................................................................... 90

7.1 Overview ............................................................................................................................................................. 907.2 BFD in Dynamic Routing.................................................................................................................................... 917.3 BFD in Static Routing ......................................................................................................................................... 927.4 BFD References................................................................................................................................................... 92

8 BFD Configuration Examples..................................................................................... 93

8.1 BFD Configuration with Routing Protocols ....................................................................................................... 938.1.1 OSPF.................................................................................................................................................... 938.1.2 IS-IS..................................................................................................................................................... 938.1.3 RSVP-TE............................................................................................................................................. 948.1.4 Single Hop BGP .................................................................................................................................. 94

8.2 BFD Configuration for Static Routes .................................................................................................................. 978.2.1 BFD Status........................................................................................................................................... 98


9

Table of Contents

9 Equal Cost Multipath (ECMP)................................................................................... 100

9.1 Overview ........................................................................................................................................................... 1009.2 ECMP Network Application ............................................................................................................................. 1009.3 ECMP Operation ............................................................................................................................................... 101

9.3.1 Dynamic Routing .............................................................................................................................. 1019.3.2 Static Routing .................................................................................................................................... 1029.3.3 Forwarding Plane Functions.............................................................................................................. 1029.3.4 Scalability .......................................................................................................................................... 102

10 Virtual Router Redundancy Protocol ...................................................................... 104

10.1 Introduction ....................................................................................................................................................... 10410.2 Operation ........................................................................................................................................................... 104

10.2.1 VRRP Parameters .............................................................................................................................. 10610.2.2 VRRP Timers..................................................................................................................................... 107

10.3 VRRP Supported Features................................................................................................................................. 10910.3.1 Implementation.................................................................................................................................. 10910.3.2 Object Tracking ................................................................................................................................. 10910.3.3 VRRP with IRB..................................................................................................................................11010.3.4 Accept Data ........................................................................................................................................111

10.4 VRRP Faults .......................................................................................................................................................11210.5 VRRP References ...............................................................................................................................................112

11 VRRP CLI Configuration Examples ......................................................................... 113

11.1 VRRP Configuration...........................................................................................................................................11311.1.1 Router1 Configuration ......................................................................................................................11411.1.2 Router2 Configuration ......................................................................................................................115

11.2 VRRP with IRB Configuration...........................................................................................................................11611.3 VRRP Status .......................................................................................................................................................118


10

About This Manual

About This Manual

This chapter discusses the objectives and intended audience of this manual, Tellabs 8600 SmartRouters Routing Protocols Configuration Guide and consists of the following sections:

Objectives

Audience

Related Documentation

Conventions

Documentation Feedback

Objectives

This manual provides an overview of the Tellabs 8600 smart routers routing protocols andinstructions on how to configure them with a Command-line Interface (CLI) using a routers consoleor remote terminal (telnet).

Audience

This manual is designed for administration personnel for configuring Tellabs 8600 smart routersfunctions with CLI. On the other hand, Tellabs 8000 intelligent network manager provides accessto equal functionality for administration personnel with a graphical user interface. It is assumed thatyou have a basic understanding of the routing protocols.

Tellabs 8600 Smart Routers Technical Documentation

The document numbering scheme consists of the document ID, indicated by numbers, and thedocument revision, indicated by a letter. The references in the Related Documentation table beloware generic and include only the document ID. To make sure the references point to the latestavailable document versions, please refer to the relevant product document program on the TellabsPortal by navigating to www.portal.tellabs.com > Product Documentation > Data Networking >Tellabs 8600 Smart Routers > Technical Documentation.


11

About This Manual

Document Title Description

Tellabs 8600 Smart RoutersATM and TDM Configuration Guide(76.860050110)

Provides an overview of Tellabs 8600 system PWE3 applications,including types, Single-Segment and Multi-Segment; PWE3Redundancy; ATM applications, including PWE3 tunneling,Traffic Management, Fault Management OAM, protection andTDM applications as well as instructions on how to configurethem with CLI.

Tellabs 8600 Smart RoutersBoot and Mini-ApplicationsEmbedded Software Release Notes(76.8600-50108)

Provides information related to the boot and mini-applicationssoftware of Tellabs 8605 smart router, Tellabs 8607 smart router,Tellabs 8609 smart router, Tellabs 8611 smart router, Tellabs8620 smart router, Tellabs 8630 smart router and Tellabs 8660smart router as well as the installation instructions.

Tellabs 8600 Smart RoutersCLI Commands Manual(76.860050117)

Provides commands available to configure, monitor and maintainTellabs 8600 system with CLI.

Tellabs 8600 Smart RoutersEmbedded Software Release Notes

Consists of the embedded software release notes of the Tellabs8600 NEs. The following embedded software release notes areavailable: Tellabs 8605 Smart Router FP1.6 Embedded SoftwareRelease Notes (76.8616-50154)

Tellabs 8607 Smart Router FP1.1 Embedded Software Re-lease Notes (76.8611-50139)

Tellabs 8609 Smart Router and Tellabs 8611 Smart RouterFP1.2 Embedded Software Release Notes (76.8612-50155)

FP4.1 Embedded Software Release Notes (76.8641-50156)of Tellabs 8620 smart router, Tellabs 8630 smart router andTellabs 8660 smart router

Tellabs 8600 Smart RoutersEquipment ManagementConfiguration Guide(76.860050118)

Provides an overview of Tellabs 8600 system HW inventory,software management, equipment protection 1+1 (CDC andSCM) as well as instructions on how to configure them with CLI.

Tellabs 8600 Smart RoutersEthernet Configuration Guide (76.8600-50133)

Provides an overview of Tellabs 8600 system Ethernetapplications, including interfaces; Ethernet forwarding (MACSwitching, Ethernet PWE3, IRB, VLAN, VPLS); Ethernet OAM;LAG; ELP as well as instructions on how to configure themwith CLI.

Tellabs 8600 Smart RoutersFault Management ConfigurationGuide (76.860050115)

Provides an overview of Tellabs 8600 system fault management,including fault source, types and status as well as instructions onhow to configure it with CLI.

Tellabs 8600 Smart RoutersFrame Relay Configuration Guide(76.860050120)

Provides an overview of Tellabs 8600 system Frame Relayapplications, including interfaces; Performance Monitoring;protection; Traffic Management as well as instructions on how toconfigure them with CLI.

Tellabs 8600 Smart RoutersHardware Installation Guide(76.8600-40039)

Provides guidance on mechanical installation, cooling,grounding, powering, cabling, maintenance, commissioning andESW downloading.

Tellabs 8600 Smart RoutersHardware Release Notes(76.8600-40027)

Consists of the hardware release notes of the network elementcomponents in Tellabs 8605 smart router, Tellabs 8607 smartrouter, Tellabs 8609 smart router, Tellabs 8611 smart router,Tellabs 8620 smart router, Tellabs 8630 smart router and Tellabs8660 smart router


12

About This Manual


Tellabs 8600 Smart RoutersInterface Configuration Guides

The Interface Configuration Guides provide an overview of theTellabs 8600 NEs interface functions, including NE supportedinterface types and equipping; interface features; configurationoptions and operating modes; fault management; performancemonitoring; interface configuration layers and port protocols aswell as instructions on how to configure them with CLI. Thefollowing interface configuration guides are available: Tellabs 8605 Smart Router FP1.6 Interface ConfigurationGuide (76.8616-50157)

Tellabs 8607 Smart Router FP1.1 Interface ConfigurationGuide (76.8611-50136)

Tellabs 8609 Smart Router Tellabs 8611 Smart RouterFP1.2 Interface Configuration Guide (76.8612-50158)

FP4.1 Interface Configuration Guide (76.8641-50159) ofTellabs 8620 smart router, Tellabs 8630 smart router andTellabs 8660 smart router

Tellabs 8600 Smart RoutersIP Forwarding and TrafficManagement Configuration Guide(76.860050122)

Provides an overview of Tellabs 8600 system IP, forwarding andtraffic management functionality, including: IP addressing; IPhosting (ARP, DHCP); IP routing (static); ACL; DifferentiatedServices (Policing, Queue Management, Shaping) as well asinstructions on how to configure them with CLI.

Tellabs 8600 Smart RoutersManagement CommunicationsConfiguration Guide(76.860050125)

Provides an overview of Tellabs 8600 system managementcommunications functions, including communication protocols:BMP; FTP; RADIUS; SNMP; SSH; TELNET as well asinstructions for configuring them with CLI.

Tellabs 8600 Smart RoutersMobile Optimization ConfigurationGuide (76.860050100)

Provides an overview of Tellabs 8600 system MobileOptimization applications as well as instructions on how toconfigure them with CLI.

Tellabs 8600 Smart RoutersMPLS Applications ConfigurationGuide (76.8600-50123)

Provides an overview of Tellabs 8600 system MPLS applications(including FRR (one-to-one and facility backup); LDP;protection and Traffic Engineering), MPLS-TP applications(including OAM, linear protection) as well as instructions onhow to configure them with CLI.

Tellabs 8600 Smart RoutersPerformance Counters ReferenceGuide (76.8600-50143)

Provides an overview of Tellabs 8600 system supportedperformance counters.


13

About This Manual


Tellabs 8600 Smart RoutersReference Manuals

The reference manuals describe the Tellabs 8600 networkelement features including: NE enclosure, baseboard, power supply modules, interfacestypes in Tellabs 8605 Smart Router FP1.6 ReferenceManual (76.8616-40099)

NE enclosure, baseboard, power supply modules, interfacesand physical LM types in Tellabs 8607 Smart Router FP1.1Reference Manual (76.8611-40067)

NE enclosure, baseboard, power supply modules, interfacesand physical LM types in Tellabs 8609 Smart Router FP1.2Reference Manual (76.8612-40100)

NE enclosure, baseboard, power supply modules, SCMs, HMand LM types in Tellabs 8611 Smart Router FP1.2 Refer-ence Manual (76.8612-40101)

NE enclosure, baseboard, power supply modules, fan mod-ule, timing module, IFMs in Tellabs 8620 Smart RouterFP4.1 Reference Manual (76.8641-40102)

NE subrack, fan modules, CDCs, line cards and IFMsin Tellabs 8630 Smart Router FP4.1 Reference Manual(76.8641-40103)

NE subrack, fan modules, CDCs, line cards and IFMsin Tellabs 8660 Smart Router FP4.1 Reference Manual(76.8641-40104)

Tellabs 8600 Smart RoutersRouting Protocols ConfigurationGuide (76.860050121)

Provides an overview of Tellabs 8600 system routing protocols,including BFD; BGP; ECMP; IS-IS; OSPF and VRRP as well asinstructions on how to configure them with CLI.

Tellabs 8600 Smart RoutersSNMP MIB Support(76.8600-50116)

Describes SNMP MIB support by the Tellabs 8600 NEs andprovides information on the supported objects and traps. Forfurther information on SNMP MIBs, see the related RFCs.

Tellabs 8600 Smart RoutersStatistic Counters Reference Guide(76.8600-50142)

Provides an overview of Tellabs 8600 system supported statisticcounters.

Tellabs 8600 Smart RoutersSynchronization ConfigurationGuide (76.860050114)

Provides an overview of Tellabs 8600 system synchronizationapplications, including physical layer Frequency Synchronization(SEC, EEC); Frequency Packet Synchronization (CES, PTP);Phase-Time Synchronization as well as instructions on how toconfigure them with CLI.

Tellabs 8600 Smart RoutersTest andMeasurement ConfigurationGuide (76.860050124)

Provides an overview of Tellabs 8600 system measurement andconnectivity verification tools, including Ethernet loopback;IP ping and traceroute; MAC swap loopback; MPLS ping andtraceroute; PLT; PWE3 loopback; VCCV (VCCV BFD, VCCVLSP ping) as well as instructions on how to configure them withCLI.

Tellabs 8600 Smart RoutersVPNs Configuration Guide(76.860050128)

Provides an overview of Tellabs 8600 system virtual privatenetwork (VPN) layer 3 applications as well as instructions onhow to configure them with CLI.

Tellabs 8000 Intelligent NetworkManager Online Help

Provides instructions on how different operations are performedwith Tellabs 8000 intelligent network manager. Describes alsodifferent parameters and controls of the Tellabs 8000 intelligentnetwork manager dialogs and windows.Note that the online help is not available on the portal but it isincorporated in Tellabs 8000 intelligent network manager.


14

About This Manual

Interface Numbering Conventions

To be able to follow more easily the feature descriptions and configuration examples given in thisdocument, see also the Tellabs 8600 system interface numbering and related figures described inTellabs 8600 Smart Routers CLI Commands Manual.

Documentation Feedback

Please contact us to suggest improvements or to report errors in our documentation:

Email: [email protected]


15

Tellabs 8600 Rebranding

Tellabs 8600 Rebranding

Starting from September 2012, Tellabs 8600 product names are being rebranded. The table belowlists previous and new product names. You may see instances of both the previous and the newproduct names in the customer documents during the transition period to the new naming system.

Previous Product Name New Product Name

Tellabs 8600 Managed Edge System Tellabs 8600 Smart Routers

Tellabs 8605 Access Switch Tellabs 8605 Smart Router






Tellabs 8660 Edge Switch Tellabs 8660 Smart Router


16

Tellabs 8600 Discontinued Products


Tellabs is announcing the Manufacture Discontinued (MD) for the following Tellabs 8600 products:


Discontinued Product ReplacementProduct/Solution

MD Notification

Tellabs 8605-A AC(81.86S8605ACCHA-R6)

Tellabs 8605-B AC(81.86S8605ACCBA-R6 Rev. B orhigher)

SC1005056-1

Tellabs 8605-A DC(81.86S-8605A-DC-R6)

Tellabs 8605-B DC(81.86S-8605B-DC-R6 Rev. A orhigher)

SC1005056-1

Tellabs 8605-A DC24(81.86S8605DC24C-R6 Rev. D)

Tellabs 8605-A DC(81.86S-8605A-DC-R6 Rev. A orhigher)

SC1002892-1

Tellabs 8605-A DC48(81.86S8605DC2BC-R6 Rev. C)

Tellabs 8605-A DC(81.86S-8605A-DC-R6 Rev. A orhigher)

SC1002892-1

Tellabs 8605-B DC24(81.86S8605DC2DC-R6 Rev. C)


SC1002892-1

Tellabs 8605-B DC48(81.86S8605DC48C-R6 Rev. B)


SC1002892-1

Tellabs 8605-D DC24(81.86S8605DC4BC-R6 Rev. C)

Tellabs 8605-D DC(81.86S-8605D-DC-R6 Rev. A orhigher)

SC1002892-1

Tellabs 8605-D DC48(81.86S8605DC4DC-R6 Rev. C)

Tellabs 8605-D DC(81.86S-8605D-DC-R6 Rev. A orhigher)

SC1002892-1

Tellabs 8609 smart router(81.86S-8609-R6 Rev. A)

Tellabs 8609 smart router R282.86S-8609-R6 Rev. A

SC1004862-1

Tellabs 8620 smart router AC(81.86S8620ACCHA-R5 Rev. B)

For most applications Tellabs 8609smart router and Tellabs 8611 smartrouter can be used, please check.

SC1005135-1

Tellabs 8620 smart router DC48(81.86S8620DC48C-R5 Rev. B)

For most applications Tellabs 8609smart router and Tellabs 8611 smartrouter can be used, please check.

SC1005136-1

Tellabs 8660 smart router subrackV3.1(81.86S-8660-R6 Rev. A)

Tellabs 8660 smart router R2subrack82.86S-8660-R6 Rev. A

SC1003044-1

IFC1-A (81.86IFC1A02024-R5Rev. B)

IFC2-B (81.86L-IFC2B-R6) ismain replacement but check IFMcompatibility.

SC1005144-1


17


Discontinued Product ReplacementProduct/Solution

MD Notification

8x10/100BASE-TX IFM(81.86MFETX82018-R6 Rev.D)

8x100/1000BASE-X R2 IFM(81.86M-IFMGEX08-R6) withIFC2

SC1005147-1

8x100BASE-X IFM(81.86MFEX082028-R6 Rev.A)


SC1005148-1

2x1000BASE-X IFM(81.86MGE0022019-R5 Rev.A)


SC1005149-1

8x1000BASE-X IFM(81.86MGE0082208-R6 Rev.B)


SC1005150-1

1xchSTM-1/chOC-3 MultiserviceIFM (81.86MS1C012203-R5 Rev.B)

4xchSTM-1/chOC-3 MultiserviceIFM (81.86MS1C042234-R6)

SC1005145-1

24xchE1/chT1Mobile OptimizationIFM (81.86ME1M242237-R6 Rev.A)

None. SC1005146-1

For details regarding Tellabs MD policy, refer to the Tellabs North America ManufacturingDiscontinued Policy found on the Tellabs Portal (www.portal.tellabs.com).


18

1 OSPF

1 OSPF

1.1 Overview

The Shortest Path First (SPF) routing algorithm is the basis for the Open Shortest Path First (OSPF)routing protocol operations to calculate the shortest path between the source and the destination.A typical OSPF network is comprised of Autonomous Systems (AS) which are groups of areas.Each OSPF router floods link-state advertisements throughout the area that contains informationabout the router interfaces and routing metrics. Each link is assigned a value that represents its cost.Each router maintains a database that describes the topology of the area. All routers that belongto the same area have an identical link-state database. OSPF quickly detects topological changesand calculates new loop-free routes.

Routers that connect areas are Area Border Routers (ABRs) and they must be part of the ASbackbone. For communication to happen between areas, each ABR advertises reachabilityinformation to all other areas.

All OSPF protocol exchanges can be authenticated. This means that only trusted routers canparticipate in the routing.

Externally derived routing data, i.e. routes learned from Border Gateway Protocol (BGP), areadvertised throughout the AS. This externally derived data is kept separate from the link-state dataof the OSPF protocol. Each external route can also be tagged by the advertising router, enabling thepassing of additional information between routers on the boundary of the AS.

OSPF can be augmented with Traffic Engineering (TE) extensions. TE extensions announceinformation about the reservation status of the links. DS-TE extensions advertise the reservationstatus per TE class for each link. That information is used when Label Switched Paths (LSPs) are setup by Resource Reservation Protocol with Traffic Engineering Extensions (RSVP-TE) signalling.


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1 OSPF

1.2 OSPF Hierarchical Routing

With hierarchical routing it is possible to build much larger OSPF networks. When networks growthe memory and computing resource requirements will grow as well. Hierarchical routing is a wayto keep the requirements for the router at an acceptable level in large networks. OSPF hides thetopology of an area from the rest of the AS. OSPF supports two-level hierarchical routing.

1.2.1 Autonomous System

AS is a group of routers under the same administrative control that share the same routinginformation.

A router that exchanges routing information with routers in other ASes is called an AS boundaryrouter. Such routers advertise the external routing information of the AS throughout the AS. Everyrouter in the AS knows the route to the AS boundary router.

1.2.2 Areas

A group of networks and hosts, together with the routers having interfaces to any one of the includednetworks, is called an area. Each area runs a separate copy of the link-state routing algorithm, i.e.each router in the area sees the topology of the area where they belong. Routers in other areas cannotsee the topology, which reduces routing traffic within the AS. The router that belongs to morethan one area is called an area border router.

OSPF backbone area, i.e. area 0.0.0.0 always contains all area border routers. Backbone areadistributes the routing information between all other areas. The backbone must be contiguous butnot necessarily physically since one can set up virtual links in order to create backbone connectivity.

OSPF supports an area type called stub area in order to lower memory consumption of the routers inthat area. External advertisements of the AS are not flooded into or through stub areas. Routing tothe external destinations of the AS in these areas is based on a default route.

Not-So-Stubby Areas (NSSAs) are similar to the OSPF stub areas but have the additional capabilityof importing AS external routes in a limited fashion. NSSA allows external routes to be floodedwithin the area but does not accept external routes from the other areas.


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1 OSPF

1.3 OSPF Hello Messages and Link-State Advertisements

OSPF router uses the Hello messages of OSPF to acquire neighbors. On Broadcast andNon-Broadcast Multiaccess (NBMA) networks the designated router for the network is elected byHello protocol. The router will setup adjacencies with new neighbors.

Link-state databases are synchronized between adjacent routers. A router periodically advertisesits link state. Link state is also advertised when the state of the router changes. Link-StateAdvertisements (LSAs) are flooded throughout the area. The advertisements depict the topologyof the AS. The flooding algorithm is reliable, ensuring that all routers in an area have exactlythe same link-state database.

The database is used to determine the route to each destination. The routes are calculated by usingthe SPF algorithm. Such calculation is used within a single area. For inter-area routes summaryLSAs are generated by ABRs for other areas. AS border routers flood information about externalroutes (external LSAs) throughout the AS except to stub areas.

The OSPF protocol runs directly over the IP network layer and uses IP protocol number 89. AllOSPF protocol packets share a common protocol header [RFC2328]. There are five different OSPFpackets: Hello, Database Description, Link-State Request, Link-State Update, Link-State Ack. Theformats are described in the previously mentioned RFC. See chapter 1.8 OSPF References for otherrelevant RFCs. A designated router that is selected by Hello protocol for multiaccess networks hasthe responsibility to announce network LSAs for the network. The designated router has adjacencieswith all the other routers in the network but the other routers do not have adjacencies with eachother. This reduces the number of adjacencies and helps OSPF to scale better.

1.4 Extensions for Support of Differentiated Services-Aware MPLSTraffic Engineering

In the networks where optimization of transmission resources is seen important, mechanisms ofDifferentiated Services can be complemented by Multiprotocol Label Switching (MPLS) TEmechanisms. To implement DS-TE in the network, OSPF must support extensions where linkreservation status per each TE class is exchanged between the routers. Opaque LSA extensions areused for this purpose. Traffic Engineering Database (TED) is used to store this information. TEDis used by Constrained Shortest Path First (CSPF) when calculating an optimal route to LSP. SeeTellabs 8600 Smart Routers MPLS Applications Configuration Guide.

1.5 OSPF Graceful Restart

OSPF graceful restart support enables OSPF router to stay on the forwarding path even if itsOSPF software is restarted. The router that is restarting sends out link-local Opaque LSA, GraceLSA, which indicates its intention to perform a graceful restart within a specified amount of time.Neighboring routers, which receive Grace LSAs, continue to announce the restarting router in theirLSAs as if it were fully adjacent, but only if the network topology remains static.


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1.6 Fast OSPF Adjacency Establishment

When a link goes up, OSPF can take quite long time to negotiate adjacencies on the link. This iscaused by two design choices in the OSPF protocol itself:

Hellos are only transmitted periodically. If a neighbor has sent a hello in the link just before a newneighbor appears, it might take almost 10 seconds, which is the default hello timer, for the firstrouter to acknowledge the existence of the new router. As reaching full adjacency takes severalround trips, this whole operation can take 30 seconds.

If a link is located in a broadcast network and no Designated Router (DR) is active, all OSPFspeakers will wait 40 seconds (the default wait time is the same as the dead time) to ensure thatthere is indeed no OSPF DR active.

This means that after a transient link failure, it can take over one minute for OSPF to reestablishthe link. The Tellabs 8600 system implements three strategies to allow the fast reestablishment ofOSPF links in case of transient failure.

Immediately replying Hello as specified in [draft-kou-ospf-immediately-replying-hello]. Withthis method, a router will immediately reply with a Hello Packet to its peer when receivinga neighbor's Hello Packet without increasing the OSPF packet traffic. Hello replies avoid thepenalty of waiting for the next periodic hello to acknowledge the state change in a neighbor. Al-though hello replies marginally increase network load when changes occur, in steady state nooverhead is incurred. To prevent malfunctioning routers from causing a hello storm, a limit canbe specified for the number of hello replies that can be sent between any two periodic hellos.

Configurable designated router (DR) wait time. This configuration parameter allows setting theDR wait time independently from the dead time. When hello acknowledgements are used, DRwait time can be very small, as the DR is guaranteed to respond almost immediately to hellosfrom the routers joining the network. If the DR wait time is set to zero, IS-IS like behavior isobtained, so that the DR can change when a new router is introduced. In general, it is desirableto keep the DR wait time value such that the DR does not accidentally change, that is, either it islonger than the hello interval or the hello acknowledgements are used and DR wait time is longerthan the time it takes for the DR to respond to the hellos, e.g. 500 ms.

Optimized Database Description (DD) exchange as specified in [draft-ogier-ospf-dbex-opt]. Withthis optimization, a router does not list an LSA in Database Description packets sent to a neighbor,if the same or a more recent instance of the LSA was listed in a Database Description packetalready received from the neighbor. This reduces Database Description overhead by about 50%in large networks, since it reduces the total number of LSA headers exchanged by about onehalf when the two routers are already nearly synchronized. This optimization does not affectsynchronization, since it only omits unnecessary information from Database Description packetsand it is fully backward compatible with OSPF.


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1.7 OSPF Unnumbered Links

The Tellabs 8600 system supports unnumbered IPv4 links as specified in [RFC1812] Unnumberedlinks are point-to-point links that connect two routers but do not have an IP address. Unnumberedlinks are used in some core networks and often for connecting equipment at customer premises.

When using unnumbered links no allocation is needed for IP addresses and they also allow easierconfiguration and network planning. On the other hand, unnumbered links in the Tellabs 8600system do not support LDP or RSVP. Maintenance is more difficult as it is not possible to ping linkaddresses; moreover, the ICMP messages show errors in unnumbered links as originating from theloopback.

Each unnumbered interface is always associated with one numbered interface. Usually theassociated interface is a loopback, however other interface types are also permitted. However if theassociated interface goes down, the operation of unnumbered interface is also hindered, hence usingloopbacks as associated interface is recommended.

The address of the associated interface is used as a source address for locally generated packetstransmitted to a unnumbered interface.

1.8 OSPF References

Reference Description

[draft-ietf-tewg-diff-te-proto] draft-ietf-tewg-diff-te-proto-07.txt (200403), Protocol extensionsfor support of Differentiated-Service-aware MPLS TrafficEngineering

[draft-kou-ospf-immediately-replying-hello]

draft-kou-ospf-immediately-replying-hello-02.txt (200701),Update to OSPF Hello procedure

[draft-ogier-ospf-dbex-opt] draft-ogier-ospf-dbex-opt-00.txt (200606), OSPF DatabaseExchange Summary List Optimization

[RFC1812] RFC1812 (199506), Requirements for IP Version 4 Routers

[RFC2328] RFC2328 (199804), OSPF version 2 (OSPFv2)

[RFC3623] RFC3623 (200311), Graceful OSPF restart

[RFC3630] RFC3630 (200309), Traffic Engineering (TE) extensions to OSPFversion 2


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2 OSPF Configuration Examples


This section gives some CLI examples of OSPF configuration in the Tellabs 8600 system.

It is advisable to always refer to Tellabs 8600 Smart Routers CLI Commands Manual for thelatest information on:

Default values to avoid unnecessary configuration;

Available configuration options and parametric range.

2.1 Basic Configuration

To enter the Configuration mode and to set up routing process use the following command.

Step 1 Activate and define OSPF instance with ID 10.

router(config)# router ospf 10

Step 2 Assign a subnet to backbone area. OSPF routing can be enabled per IPv4 subnet basis. Each subnetcan belong to one particular OSPF area.

router(cfg-ospf[10])# network 10.0.0.0/8 area 0.0.0.0

Step 3 Each router needs to be configured with a unique router ID. This step is not necessarily needed sincethe OSPF router ID is selected automatically if this command is not entered. The highest loopbackaddress is used as the OSPF router ID by default.

router(cfg-ospf[10])# ospf router-id 2.3.4.5router(cfg-ospf[10])# exit


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2.2 Interface Configuration

The following is an example of OSPF settings at interface level.

Step 1 Set the OSPF cost to 10.

router(config)# interface fe 3/0/1router(cfg-if[fe3/0/1])# ip ospf cost 10

Step 2 Configure the Ethernet port as a point-to-point network.

router(cfg-if[fe3/0/2])# ip ospf network point-to-point

Step 3 Priority for designated router selection is set to 3. In multi-access networks a router priority is set todetermine the designated router for the network.

router(cfg-if[fe3/0/1])# ip ospf priority 3

Step 4 Set the interval between Hello packets hello-interval to 3 seconds.

router(cfg-if[fe3/0/1])# ip ospf hello-interval 3

Step 5 Set the interval during which, if no Hello packets are received a neighbor is declared not available.In this example the dead-interval is set to 10 seconds.

router(cfg-if[fe3/0/1])# ip ospf dead-interval 10router(cfg-if[fe3/0/1])# exit

2.3 Area Configuration

An AS can be split into multiple areas in order to reduce LSA traffic and the size of the LSAdatabases, the routers need to maintain.

In chapter 2.1 Basic Configuration the network area command was illustrated by connecting thenetwork to the OSPF backbone area.

Step 1 Assign subnet to area 1.1.1.1.

router(config)# router ospf 10router(cfg-ospf[10])# network 10.0.0.0/8 area 1.1.1.1

Step 2 Set an area as a stub area.

router(cfg-ospf[10])# area 1.1.1.1 stub

There are no external routes in an OSPF stub area, so you cannot redistribute from another protocolinto a stub area. An NSSA allows external routes to be flooded within the area. These routes arethen leaked into other areas. The external routes from other areas still do not enter the NSSA. Toconfigure area as NSSA use the following command.

Step 1 Note that with this command it is possible to define if the router will translate Type-7 LSAsreceived from the NSSA into Type-5 LSAs. Also to define whether or not to redistribute externalroutes to NSSA.

router(cfg-ospf[10])# area 1.1.1.1 nssarouter(cfg-ospf[10])# exit


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2.4 Authentication

To enable the OSPF authentication for an interface use the following commands. These commandsactivate Message Digest Authentication (MDA), which is a cryptographic authentication.

Step 1 This enables the OSPF packet to use authentication on the interface. MDA scheme is selected.

router(config)# interface fe 3/0/1router(cfg-if[fe3/0/1])# ip ospf authentication message-digest

Step 2 Set the key and key ID for an interface.

router(cfg-if[fe3/0/1])# ip ospf message-digest-keychain router(cfg-if[fe3/0/1])# exit

2.5 TE Configuration

OSPF-TE is used together with RSVP-TE in traffic engineering applications. A complete exampleof this is given in Tellabs 8600 Smart Routers MPLS Applications Configuration Guide, whereasthis guide illustrates the configuration needed for OSPF-TE. For instance, the bandwidth constraintsand bandwidth constraints model configuration are explained in the previously mentioned guide.TE is enabled as a default.

OSPF is used to advertise networks and information about TE classes.

Step 1 Enable traffic engineering extensions.

router(config)# router ospf 10router(cfg-ospf[10])# traffic-eng

Step 2 Enable constraint-based shortest path first calculation.

router(cfg-ospf[10])# cspf

Step 3 You can specify cspf tie-break method (used if more than one candidate link satisfies all the routeconstraints). This sets preferred path to be the one with the largest minimum available bandwidthratio. This command is optional. Default is random.

router(cfg-ospf[10])# cspf tie-break least-fillrouter(cfg-ospf[10])# exit

2.6 Graceful Restart Configuration

Graceful restart is enabled by default. Default parameters are optimized to most networks and theyshould not be modified unless absolutely necessary. You can configure graceful restart featurewith the following commands.

Step 1 Enable graceful restart feature and specify grace period to be 250 seconds.

router(config)# ospf restart grace period 250

Step 2 Acts as helper only if received grace period is less than 300 seconds.

router(config)# ospf restart helper max-grace-period 300


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2.7 Fast OSPF Convergence

Traditionally, OSPF has slow convergence if multiple changes occur within a short period of time.Usually the OSPF installations have the following default values:

SPF triggering delay: 5 s

SPF hold time: 10 s (minimum time between two consecutive SPF calculations)

MinLSInterval: 5 s

This means that the first change of a kind is updated within 5 seconds, but later changes can take5+10=15 seconds.

The Tellabs 8600 system allows the use of exponential delay for these parameters. As a result, thesystem allows rapid response to a small number of events while preventing overload when multipleevents occur continuously.

Both SPF and LSA refresh timers are based on exponential curves. Both of them have threeparameters:

Initial delay

Multiplier

Maximum delay

The first event is n=0 whereas the following events are 1, 2, 3... An event number is set to zerowhen 2 * maximum delay has elapsed without further events.

The SPF delay is calculated per area but the LSA refresh time per each individual LSA. The formulaused for this is as follows:

for n=0: delay = initial

for n>0: delay = MAX(initial + multiplier*2^(n-1), max_delay)

The delay is calculated from the previous SPF calculation or from the previous refresh of LSA.However, if an initial value is non-zero, the event will not be executed until now+initial (even if theprev_event+delay would be before that). This allows the collecting of multiple events to a singleexecution. The values are specified as milliseconds.

The traditional OSPF values could be specified as stated in the following table.

init mul max

SPF 5000 10000 10000

LSA refresh 0 5000 5000

The Tellabs 8600 system uses more optimized values for SPF.

init mul max

SPF (non-VRF) 200 100 10000

SPF (VRF) 500 2000 10000


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In the case of non-VRF SPF this would yield (for the constantly repeating event) the following SPFdelays: 200, 300, 400, 600, 1000, 1800, 3400, 6600, 10000, 10000, 10000, ...

LSA refresh timers are not optimized by default, as OSPF architectural constant MinLSArrivalmust be set (network wide) so that LSAs are not generated faster than MinLSArrival permits themto be received.

The default OSPF LSA refresh parameters are reasonable, if it is assumed that only single changesper network occur quickly. However, sometimes it might be necessary to update the router LSAsfaster. In such cases, reasonable parameters might be as follows: LSA refresh: init 0, mul 400, max5000. This would yield delays 0, 400, 800, 1600, 3200, 5000, 5000...

Please note that LSA refresh timer does not apply to the initial generation of LSA (which is, as thename says, not a refresh). N is zero for first refresh.

However for this to work, all NEs must set MinLSArrival to values less than 400 ms (for example200 ms). The default OSPF value for MinLSArrival is one second. Initial delay of 0 ms isreasonable, but to ensure that multiple events can update router LSA sufficiently fast, the multipliershould be sufficiently low.

Normally updates are rate-limited to one LSA update per 33 ms. Thus, it may become necessaryto allow faster flooding. Setting the pacing timer to 10 ms would allow 10 updates for each 100ms period.

Step 1 Set the above parameters according to the examples.router(config)# router ospf Xrouter(cfg-ospf[X])# timers spf router(cfg-ospf[X])# timers lsa refresh router(cfg-ospf[X])# timers lsa arrival router(cfg-ospf[X])# timers pacing flood router(cfg-ospf[X])# exit

Step 2 Take these steps to convene the OSPF setup quickly.router(config)# router ospf 10router(cfg-ospf[10])# timers spf 200 100 10000router(cfg-ospf[10])# timers lsa refresh 0 400 5000router(cfg-ospf[10])# timers pacing flood 10router(cfg-ospf[10])# exit

2.8 Fast OSPF Adjacency Establishment Configuration

2.8.1 Enabling Hello replies

To enable Hello replies in one or all interfaces use the following commands as it corresponds.

Step 1 Specify that a maximum of 15 Hello replies per Hello interval for all interfaces are permitted.router(config)# router ospf 10router(cfg-ospf[10])# hello-reply 15router(cfg-ospf[10])# exit

Step 2 Specify that a maximum of 15 Hello replies per Hello interval are permitted for the specifiedinterface.

router(config)# interface fe 0/0


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router(cfg-if[fe0/0])# ip ospf hello-reply 15router(cfg-if[fe0/0])# exit

2.8.2 Designated Router (DR) Wait Time Configuration

When the link has only two OSPF speakers, DR wait time can be optimized entirely. This can beaccomplished by running the link in point-to-point mode. This is also possible for Ethernet. This isthe preferred configuration which allows the fastest OSPF link recovery times. To use point-to-pointmode in a link that naturally is multicast or broadcast use the following command.

Step 1 Enable the point-to-point mode.router(config)# interface fe 0/0router(cfg-if[fe0/0])# ip ospf network point-to-pointrouter(cfg-if[fe0/0])# exit

When the link has more than two routers but only one needs to be DR (this would be the uplinkconfiguration, where the network is useless unless an uplink router is available), the DR wait timecan be configured to zero. This configuration is also allowed if traffic interruption is permittedwhenever a new DRcapable router (DR priority is not zero) joins the network. To configure the DRwait time for one or all interfaces use the following commands as it corresponds.

Step 1 Set the DR wait time to zero for all interfaces.router(config)# router ospf 10router(cfg-ospf[10])# wait-time 0router(cfg-ospf[10])# exit

Step 2 Set the DR wait time to zero for the specified interface.router(config)# interface fe 0/0router(cfg-if[fe0/0])# ip ospf wait-time 0router(cfg-if[fe0/0])# exit

The above configuration is only recommended in those cases when:

There is only one DR and all the other routers in the subnet have DR priority set to zero, but notif the network should function with loss of the designated DR. The configuration would makesense if DR is in the RNC front node and without it the network would be useless.

IS-IS behavior is desired and traffic interruption is permitted when a new router joins the subnet.

The recommended configuration, when the point-to-point mode cannot be used, is to enable thehello acknowledgements and configure the DR wait time to a small value, in the range of 300-500ms. When the hello acknowledgements are also enabled, 500 ms is enough time for the DR torespond, if any DRs exist. To configure the DR wait time for one or all interfaces use the followingcommands as it corresponds.

Step 1 Set the DR wait time to 500 ms for all interfaces.router(config)# router ospf 10router(cfg-ospf[10])# wait-time 500router(cfg-ospf[10])# exit

Step 2 Set the DR wait time to 500 ms for the specified interface.router(config)# interface fe 0/0router(cfg-if[fe0/0])# ip ospf wait-time 500router(cfg-if[fe0/0])# exit


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To get the full benefit of these optimizations, fast OSPF convergence should be configured asspecified below, there is no use in having the OSPF adjacencies for up in subsecond time frame, ifthe update of the network LSA takes from 5 to 10 seconds and the additional SPF calculation adds30 seconds. See the two following examples.

The first example illustrates a case with a ring of point-to-point links and a relatively small OSPFnetwork that allows the use of aggressive timers.

Step 1 Enable the point-to-point mode.

router(config)# interface fe 0/0router(cfg-if[fe0/0])# ip ospf network point-to-pointrouter(cfg-if[fe0/0])# exit

Step 2 Generate LSA updates quickly.

router(config)# router ospf 10router(cfg-ospf[10])# timers lsa refresh 0 150 5000

Step 3 Default value.

router(cfg-ospf[10])# timers spf 200 100 1000

Step 4 Accept LSAs quickly.

router(cfg-ospf[10])# timers lsa arrival 50

Step 5 Disable LSA pacing.

router(cfg-ospf[10])# timers pacing flood 0

Step 6 Permit hello replies.

router(cfg-ospf[10])# Hello-reply 15router(cfg-ospf[10])# exit

In the second example , there is a multiaccess network and a relatively small OSPF network thatallows the use of aggressive timers.

Step 1 Enable the point-to-point mode.

router(config)# interface fe 0/0router(cfg-if[fe0/0])# ip ospf wait-time 300router(cfg-if[fe0/0])# exit

Step 2 Generate LSA updates quickly.

router(config)# router ospf 10router(cfg-ospf[10])# timers lsa refresh 0 150 5000

Step 3 Default value.

router(cfg-ospf[10])# timers spf 200 100 1000

Step 4 Accept LSAs quickly.

router(cfg-ospf[10])# timers lsa arrival 50

Step 5 Disable LSA pacing.

router(cfg-ospf[10])# timers pacing flood 0

Step 6 Permit hello replies.

router(cfg-ospf[10])# Hello-reply 15


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The OSPF parameters and hello reply statistics are available from the show ip ospf interfacecommand 2.10 OSPF Status .

2.9 OSPF Unnumbered Links Configuration

The following is an example showing how to configure an OSPF unnumbered link for an interface.

Step 1 Set the loopback interface.

router(config)# ip interface lo0router(cfg-if[lo0])# ip address 1.1.1.1/32router(cfg-if[lo0])# no shutdownrouter(cfg-if[lo0])# exit

Step 1 Select the interface to be configured.

router(config)# interface so 10/0/0

Step 2 Specify that the IP address is borrowed from the loopback interface. The unnumbered interface isautomatically taken into OSPF routing when the associated loopback is taken.

router(cfg-if[so10/0/0])# ip unnumbered lo0router(cfg-if[so10/0/0])# no shutdownrouter(cfg-if[so10/0/0])# exit

The following is an example on how to enable OSPF routing on the interface so10/0/0.

Step 1 Activate and define OSPF instance with ID 10.

router(config)# router ospf 10

Step 2 Assign a subnet to the backbone area.

router(cfg-ospf[10])# network 1.1.1.1/32 area 0

OSPF routing can be enabled per IPv4 subnet basis. Each subnet can belong to one particularOSPF area.

The loopback address is the same for the node and for all the interfaces, so if there are customerinterfaces that you want to use as unnumbered, but do not wish to have them OSPF enabled, use adifferent loopback interface for those interfaces.

OSPF can also be disabled from the customer interfaces by setting customer interfaces to passivemode using the following command

Step 1 Set the customer interface to passive mode.

router(config)# router ospf 10router(cfg-ospf[10])# passive-interface so 10/0/0router(cfg-ospf[10])# exit


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2.10 OSPF Status

OSPF information can be inspected using the OSPF options of the show command. The following isan example showing the OSPF interface parameters and statistics:

Fig. 1 OSPF Parameters and Statistics


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3 Border Gateway Protocol


3.1 Overview

Border Gateway Protocol (BGP) is a Routing Protocol that is used to create an inter-domain routingbetween autonomous systems or inside of an Autonomous System (AS). The Tellabs 8600 systemimplements BGP version 4 (BGP-4) according to [RFC1771]. The main purpose of BGP is toexchange network reachability information, including a list of the autonomous systems and pathsconnectivity to other BGP routers. The information is mainly used to construct a network topologyoutlining a loop free connectivity, where routing policy decisions can be enforced.

BGP supports two different types of routing information exchanges, interior BGP (iBGP) andexterior BGP (eBGP).

An iBGP is used between BGP routers inside a single AS. To prevent routing loops, iBGP to iBGPadvertisements are not allowed within the iBGP routers. Therefore, in an AS, the iBGP routers musthave either a full-mesh connectivity, or use Router Reflector (RR), or confederations instead.

An eBGP is used to exchange routing information between routers within different autonomoussystems. In a typical case, eBGP routers are directly connected.

Fig. 2 BGP Topology

Fig. 2 illustrates a classical BGP network topology, where all routers within the AS65100 are iBGPpeers. Route information exchange between AS65100, AS65200 and AS65300 is accomplishedthrough eBGP.


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A simple scenario of mobile backhaul BGP application with the Tellabs 8600 system deployment(inter-AS with multihoming connectivity) is presented in the following diagram. Mobile backhaultypical applications use RR, which is described in 3.8.1 Route Reflector.

Fig. 3 Inter-AS BGP in Mobile Deployments

Another more complex mobile backhaul network scenario using BGP is presented in the followingdiagram.


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Fig. 4 Complex Mobile Network BGP Application

In the transit autonomous systems, all P-routers on the path used by transit traffic must eitherparticipate in iBGP routing, or the Autonomous System Border Router(s) (ASBR) of the transitAS must use MPLS tunneling (BGP free core).

The following table defines the terms used in the BGP section including CLI configuration examples.

Terminology Definition

Autonomous System (AS) An AS is defined as a consistent set of routers that are administered by asingle operator/ISP and advertise a coherent interior routing plan to theexternal routers.

AS confederation It is a logical AS formed by multiple sub-autonomous systems.

Attribute It is a parameter used in BGP to describe detailed characteristics of aprefix/route.

BGP router Refers to a router implementing BGP. When two or more BGP routersestablish a BGP session, they are called as either BGP speakers, BGPpeers or BGP neighbors.

BGP routing process Refers to an action of setting a router to become a BGP speaker.

Cluster A logical area formed by route reflector(s) and clients.

Multihoming Refers to multiple sites connectivity with aim to increase reliability.

Non-transitive Refers to a characteristic of a BGP attribute not being sent past the ASthat received the attribute in case.

Route reflection Route reflection is the advertisement of routes between iBGP peers by adesignated router, known as router reflector.


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Terminology Definition

Route Reflector (RR) A dedicated BGP router tasked to re-advertise routing information to otheriBGP peers.

RR client An iBGP router operation of which relies on RR to re-advertise its routinginformation to the entire AS and also to learn about other routes fromthe network.

Transitive Refers to a BGP attribute being sent past the AS that is receiving it, due tothe fact that the attribute is unknown to BGP implementation.

Well-known attribute A BGP attribute that is required to be known by all BGP implementations.

Well-known discretionary Refers to a set of well-known attributes that may or may not be included inevery update message.

Well-known mandatory Refers to a set of well-known attributes that must be included in all updatemessages exchanged by BGP routers.

A peering session is used to advertise network reachability information, which contains a list ofnetworks and information on how the networks can be reached. Initially, when the connection isestablished, the BGP peer routers exchange their full routing tables. After a connection has beenestablished, only route changes (incremental or triggered) are advertised.

In order to exchange routing information, a BGP peering session has to be established between twoBGP routers. BGP utilizes TCP as a transport layer protocol and the TCP session is carried on port179. Two BGP routers form a TCP connection between each other and exchange messages toopen and confirm the peering session parameters. The session is maintained by sending keepalivemessages, and in case of errors or in other special conditions, a notification message is generated.

John W. Stewart's book BGP4 Inter-Domain Routing in the Internet is recommended for thoseseeking more operational details and how to use BGP.

3.2 BGP Attributes

The terms used in this chapter are defined in 3.1 Overview. In BGP, the attributes play an essentialrole to the operation of the protocol by making BGP flexible for later extensions, so that newfeatures can be added without changing the base protocol. The BGP attributes are a set of parametersdescribing the detailed characteristics of a prefix or path information that can be used, for example,to enforce path selection and routing policy. The BGP attributes can be classified into the followingfour groups [RFC4271]:

1. Well-known mandatory. These attributes are mandatory and must be recognized by all BGProuters. They are included in all update messages exchanged by BGP peers.

ORIGIN

AS_PATH

NEXT_HOP

2. Well-known discretionary. These attributes must be supported by all BGP routers and may ormay not be included in every update message.

LOCAL_PREFERENCE

ATOMIC_AGGREGATE


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3. Optional transitive. These attributes are transitive between autonomous systems and are notmandatory to be recognized by all BGP routers. When sent in an update message and the re-ceiving router does not recognize them, the attributes are sent over to the next AS.

AGGREGATOR

COMMUNITY

4. Optional non-transitive. These attributes may be recognized by some, but not by all BGProuters. When an update message containing any attribute of this group is received by a routernot recognizing it, the update will be advertised to other BGP peers without the unrecognizedattribute.

MED (Multi-Exit-Descriminator)

3.2.1 ORIGIN Attribute

ORIGIN is a well-known mandatory attribute that indicates the origin of routing information orhow a given route has been learned by BGP. That is, the attribute is generated by the AS originatingthe associated routing information and it is included in the update message of all BGP speakersadvertising this information to other BGP speakers. The attribute can be used to influence BGP pathpreference selection. By the way in which a route is learned by BGP, the ORIGIN attribute canassume three possible values listed below in the precedence order:

IGP (Interior Gateway Protocol), which indicates that the prefix is interior to the AS of origina-tion;

EGP ( Exterior Gateway Protocol), which indicates that the prefix is originated from an EGPprotocol.

INCOMPLETE, which indicates the prefix has been learned via other sources.

3.2.2 AS PATH Attribute

AS_PATH is a well-known mandatory attribute that identifies those autonomous systems throughwhich a route being announced has traversed. The attribute will be handled differently depending onwhether the route is being originated, or propagated.

When a BGP router originates a route, the AS_PATH information is empty in all the updates sentwithin the AS where the BGP router is located. If the originating router has an eBGP sessionstowards neighboring autonomous systems, then a router will add its AS number when advertisingthe route information to the neighbors (BGP routers).

When a route is being propagated to BGP peers within an AS, a peer propagating this route is notallowed to modify the AS_PATH attribute associated with a route. However, if a route is beingpropagated from one local AS to another, i.e. when a route traverses an AS border, a border BGProuter modifies the attribute by adding the AS number of the traversed AS. An appended AS numberappears first in the AS_PATH information as illustrated in the following topology.


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Fig. 5 AS Path Attribute

The set of autonomous systems, through which a route has traversed in AS_PATH information,allows the receiving BGP router to identify the autonomous systems a route has traversed. Toavoid routing loops, BGP routers do not accept advertisements that contain a local AS number asillustrated in Fig. 5. Thus the attribute is used for routing loop detection and prevention. Routingpolicy is another application of the AS_PATH attribute in BGP.

3.2.3 NEXT HOP Attribute

NEXT_HOP is a well-known mandatory attribute, which carries information on how to reach theadvertised network in the form of an IP address of the next router towards the destination.

By default, the Tellabs 8600 system follows standard conventions ([RFC4271] for basic rules,[RFC2796] for route reflection, [RFC3065] for confederations) on setting the NEXT_HOP attribute.A somewhat inaccurate assumption is that the NEXT_HOP is changed usually when advertising toeBGP neighbors, while advertisements to iBGP neighbors do not change the attribute. For VPNv4Subsequent Address Family Identifier (SAFI), the NEXT_HOP is also changed by default on optionD eBGP iBGP advertisements. Setting the NEXT_HOP for VPNv4 route to any local address,also changes the MPLS label to a locally-assigned label.

A manual control of the NEXT_HOP attribute is available via several options, which are providedbelow in order of preference. If multiple options are set, then the ones listed first take precedence:

1. Set statement in route-map ("set ip next-hop A.B.C.D")

2. Unchanged next-hop configuration ("router bgp x / address-family / neighborX.X.X.X transparent-next-hop")


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3. Next-hop-area configuration ("router bgp x / address-family / neighbor X.X.X.X next-hop-area Y")

4. Next-hop-self configuration ("router bgp x / address-family / neighbor X.X.X.X next-hop-self")

From the configuration options listed above, the most complex is the next-hop-area.Thisoption is intended to allow more fine-grained control of the NEXT_HOP setting on the borders ofvarious types of regions. It allows using both the source and the destination peers as part of thepolicy. The next-hop-area option works as follows:

When no next-hop-area is configured to a source or destination peer, the NEXT_HOP pro-cessing is per regular rules.

If both source and destination have next-hop-area configured, then:

1. If it is the same area, this is taken as a request to keep the NEXT_HOP unchanged. Thisoverrid

Documents

Routing Protocols Conﬁguration Guide