Router 1
`
`44/W/A00/z"
`
`A
`
`0 DETAILED COVERAGE OF INTERNETWORKING
`
`LEGACY SYSTEMS
`
`I PRACTICAL INSIGHT INTO ALL ROUTING PROTOCOLS,
`
`INCLUDING RIP, EIGRP, OSPF, AND BGP
`
`0 EXTENSIVE DISCUSSION OF INTERNETWORKING
`
`DESIGN
`
`GEORGE C. SACKETT
`
`1
`
`ARISTA 1109
`
`1
`
`ARISTA 1109
`
`

`
`2
`
`

`
`“This reference manual will serve as an excellent guide for any field engi-
`neer looking for a concise answer to almost any Cisco-related problem. For
`the mid-level to senior engineer this book will be an excellent research
`and learning tool when considering implementation of a new Cisco-based
`technology solution.”
`
`—E. Gary Hauser Jr. Senior Instructor/Consultant,
`CCIE #4489, CCSI#9.9166
`Chesapeake Computer Consultants, Inc.
`
`“The one reference you take into the field. A compact source of solutions
`to the most common Cisco design and configuration questions. The first
`place to look when researching your networking projects.”
`
`——Jim Bender, Internetworking Consultant, RPM Consulting
`
`3
`
`

`
`Cisco Router
`Handbook
`
`George C. Sackett
`
`‘
`McGraw-Hill
`New York - San Francisco 0 Washington, D.C. - Auckland
`Bogota - Caracas - Lisbon ~ London - Madrid - Mexico City
`Milan - Montreal - New Delhi - San Juan - Singapore
`Sydney - Tokyo - Toronto
`
`4
`
`

`
`Library of Congress Cataloging-in-Publication Data
`
`Sackett, George C.
`The Cisco router handbook George Sackett.
`p.
`cm.
`Includes index.
`ISBN 0-O7-058098-7
`2. Computer network protocols.
`1. Routers (Computer networks)
`3. Internetworking (Telecommunication)
`I. Title.
`TH5105.543.S23
`1999
`004.6'2—dc21
`‘
`
`99-33212
`CIP
`
`McGraw-Hill
`,A Division of'17u3 McGrmu-Hi1lCompam’cs
`
`Copyright © 2000 by The McGraw-Hill Companies, I11c. All Rights Reserved. Printed in
`the United States of America. Except as permitted under the United States Copyright Act
`of 1976, no part of this publication may be reproduced or distributed in any form or by
`any means, or stored in a data base or retrieval system, without the prior wfitten permis-
`sion of the publisher.
`1234567890 DOC/DOC 90432109
`
`ISBN 0-07-058098—7
`
`7712 sponsoring editor for this book was Steven Elliot and the production
`supervisor was Clone Stanley. It was set in Century Schoolbook by D&G Limited, LLC.
`
`Printed and bound by R. R. Donnelley & Sons Company.
`
`McGraw-Hill books are available at special quantity discounts to use as
`premiums and sales promotions, or for use in corporate training programs.
`For more information, please write to Director of Special Sales, McGraw-Hill,
`11 West 19th Street, New York, NY 10011. Or contact your local bookstore.
`Throughout this book, trademarked names are used. Rather than put a trademark symbol
`after every occurrence of a trademarked name, we use names in an editorial fashion only,
`and to the benefit of the trademark owner, with no intention of infringement of the trade-
`mark. Where such designations appear in thisbook, they have been printed with initial
`caps.
`
`Information contained in this work-has been obtained by The McGraw-Hill Companies,
`Inc. (“McGraw-Hill”) from sources believed to be reliable. However, neither McGraw-Hill
`nor its authors guarantees the accuracy or completeness of any information published
`herein and neither McGraw-I-Iill nor its authors shall be responsible for any errors, omis-
`sions, or damages arising out ofuse of this information. Th.is work is published with the
`understanding
`that
`McGraw-Hill and its authors are Supplying information but are not attempting to ren-
`der engineering or other professional services. If such services are required, the assis-
`tance of an appropriate professional should be sought.
`
`This book is printed on recycled, acid-free paper containing a minimum of 50
`F‘
`‘Q percent recycled de-inked fiber.
`
`5
`
`

`
`This book is dedicated to my wife, Nancy, for her consistent strength,
`direction, support, encouragement, understanding and for creating a life
`with me filled with love and affection.
`
`6
`
`

`
`
`
`ACKNOWLEDGMENTS
`
`First and foremost I must thank my wife Nancy for her incredible sup-
`port on this time consuming and lengthy project. She is the best. Secondly
`I must extend my appreciation to Steve Elliot, Executive Editor at
`McGraw-Hill, who throughout this project was able to keep me driven,
`focused, and excited about the handbook. I would also like to acknowledge
`Tony Costa CCIE# 4140 and Andrew Cassera CIT (CCIE in training) for
`their much needed contribution to this project. Their efforts and input
`were greatly appreciated. I would also like to thank Gary Stewart, Tech-
`nical Illustrator with Cisco Systems Icons Document Resource Connection
`department for not getting totally annoyed with my request for hardware
`illustrations and Cisco Systems icons for this project. Not to be forgotten
`are the talented people who have made this Cisco Systems the definitive
`networking company. Their insight, dedication and fortitude have not only
`created a multibillion dollar company but have forged cultural and social
`change not seen since the availability of the automobile to the masses. All
`their efforts are greatly appreciated. Finally, I must thank all my children,
`Chelsea, Pamela, James, Meredith and Abigail for accepting my absence,
`irritability after many sleepless nights, and for the many times they have
`made me smile.
`
`
`
`
`
`
`
`
`
`7
`
`

`
`.a
`
`\l\lG‘G‘@U1-hWWNN
`
`CONTENTS
`
`Foreword
`
`Chapter 1
`
`Cisco IOS Software
`Benefits
`
`Scalability
`Adaptiveness
`Access Support
`Performance Optimization
`Management
`Security
`Packaging
`Feature Sets
`Feature Packs
`
`Features Supported
`Protocols
`
`Management
`Multimedia and 00S
`Secure Data Transmission
`
`Support for IBM Networking Environments
`IP Routing Protocols
`Bridging
`Packet Switching
`NetFlow Switching
`ATM
`
`Dial-on-demand Routing
`Access Server
`LAN Extension
`
`Cisco Router Hardware
`
`Cisco Router Network Hierarchy
`‘Core
`Distribution
`
`Access
`
`_
`
`Online Insertion and Removal (OIR)
`Supported Platforms
`OIR Process
`I
`Exceptions to Using OIR
`
`8
`
`

`
`Contents
`
`Cisco 12000 Series
`Cisco 12004 Series
`Cisco 12008 Series
`Cisco 12012 Series
`
`12000 Usage
`12000 Switch Processors
`
`12000 Memory
`12000 Line Cards
`
`12000 Software Support
`Cisco 7500 Series
`Cisco 7505 Series
`Cisco 7507 Series
`Cisco 7513 Series
`
`7500 Usage
`7500 System Processors
`7500 Memory
`7200 Series
`
`7200 Usage
`7200 Network Processing Engine
`7200 Memory
`7000 Series
`
`7000 Usage
`7000 System Processors
`7000 Memory
`Cisco 7x00 Series Interface Processors
`
`'
`
`7x00 ATM Interface Processor (NF)
`7x00 Channel Interface Processor 2 lClP2)
`7x00 Channelized T3 Interface Processor (CT3IP)
`7x00 Ethernet Interface Processor (ElP|
`7x00 Fast Ethernet Interface Processor (FElP) and FEIPZ
`7x00 FDDI Interface Processor (FIP)
`»
`7x00 Fast Serial Interface Processor (FSIPI
`
`7x00 High-Speed Serial Interface[HSSI) Interface
`Processor (HIP)
`7x00 Multichannel Interface Processor (MIP)
`
`7x00 Packet OC-3 Interface Processor (POSIP)
`7x00 Service Provider MIP (SMlP)
`7x00 Standard Serial Interface Processor (SSIP)
`7x00 Token Ring Interface Processor (TRIP)
`7x00 Versatile Interface Processor 2 (VIP2)
`
`29
`30
`30
`32
`
`32
`34
`
`35
`36
`
`42
`43
`44
`44
`45
`
`46
`47
`48
`49
`
`51
`51
`51
`52
`
`53
`53
`54
`55
`
`55
`56
`
`5‘)
`
`61
`61
`
`62
`63
`
`64
`65
`66
`67
`67
`
`9
`
`

`
`Contents
`
`Cisco 7x00 Series Port and Service Adapters
`7x00 ATM OC—3
`
`7x00 ATM-Circuit Emulation Services (ATM-CES)
`7x00 100VG-AnyLAN
`7x00 ISDN Basic Rate Interface (BRI)
`7x00 Channelized Tl/El lSDN PRI
`7x00 Ethernet IOEaseT
`7x00 Ethernet l0EaseFL
`7x00 Fast Ethernet
`
`7x00 Synchronous Serial
`7x00 Single Port Molex 200-pin Receptacle
`7x00 Synchronous Serial E1—G.703/G.704
`7x00 Token Ring
`7x00 FDDI
`7x00 HSSI
`
`7x00 Compression Service Adapter
`4000 Series
`
`4000 Usage
`4000 Processors
`
`4000 Memory
`3600 Series
`
`3600 Usage
`3600 Processors and Memory
`2600 Series
`
`2600 Usage
`2600 Processor
`
`2600 Memory
`2500 Series
`
`2500 Usage
`2500 Processor and Memory
`1600 Series
`
`1600 Usage
`i600 Processor and Memory
`
`700M Family of Access Routers
`
`Chapter 3
`
`Cisco Router Network Design
`
`The Netvvorklnfrastructure Lifecycle
`Executive Corporate Vision
`. Gather Network Infrastructure Information
`
`Determine Current Network Requirements
`
`10
`
`

`
`Assess Current Network Operational Processes
`Research Plans for New Applications
`Identify Networking Technologies
`Define a Flexible Strategic/Tactical Plan
`Developing an Implementation Plan
`Management and Review
`Design Criteria
`The Current LAN/Campus Network Trend
`\XIAN Design Trends
`Remote Network Trends
`
`Application Availability Versus Cost-Effectiveness
`Application Profile
`Cost-Efficiency
`Network Devices and Capabilities
`Bridging and Routing
`Switching
`Backbone Considerations
`Distributed Services
`Local Services
`
`Selecting Routing Protocol
`Network Topology
`Addressing and Route Summarization
`Route Selection
`
`The Concept of Convergence
`Network Scalability
`Security
`
`Chapter 4
`
`IP Routing Protocol Design
`
`RIB RlP2, and IGRP Network Design
`RIP, RIPZ, and IGRP Topology
`RIB RIPZ, and IGRP Addressing and Summarization
`‘RIP, RlP2, and [IGRP Route Selection and Convergence
`RIP, RIPZ, and IGRP Network Scalability
`EIGRP Network Design
`EIGRP Topology
`EIGRP Addressing and Summarization
`EIGRP Route Selection
`EIGRP Convergence
`EIGRP Scalability
`EIGRP Scalability
`EIGRP Security
`
`11
`
`

`
`Contents
`
`OSPF Network Design
`OSPF Topology
`OSPF Addressing and Summarization
`OSPF Route Selection
`OSPF Convergence
`OSPF Scalability
`OSPF Security
`
`Chapter 5
`
`Frame Relay Network Design
`
`Hierarchical Design of Frame Relay lnternetworks
`Frame Relay Scalability
`‘
`Frame Relay Management
`Frame Relay Performance
`Frame Relay Network Topology
`Frame Relay Star Topology
`Frame Relay Fully Meshed Topology
`Frame Relay Partially Meshed Topology
`Frame Relay Fully Meshed Hierarchical Topology
`Frame Relay Hybrid Meshed Hierarchical Topology
`Broadcast Traffic Issues
`Performance Considerations
`Determining Maximum rate
`Committed information Rate (CIR)
`FECN/BECN Congestion Protocol
`Virtual Subinterface and Multiprotocol Management
`SNA Support
`Boundary Network Node (BNN)
`Boundary Access Node (BAN)
`FRAS Host Support
`
`Chapter 6
`
`ATM lnternetworking Design
`
`LAN Emulation (LANE)
`LAN Emulation Client (LEC)
`LAN Emulation Configuration Server (LECS)
`LAN Emulation Server (LES)
`Broadcast Unknown Server (BUS)
`LANE Design Considerations
`Network Support
`Addressing
`LANE ATM Addresses
`
`12
`
`

`
`Contents
`
`Cisco’s Method of Automatically Assigning ATM
`Addresses
`
`Using ATM Address Templates
`Rules for Assigning Components to Interfaces
`and Subinterfaces
`
`Redundancy in LANE Environments
`
`Chapter 7
`
`Data Exchange Interface lDXl)
`Supported Modes
`DXl Addressing
`Classical lP
`
`Multiprotocol over ATM (MPOA)
`Multiprotocol Client (MPCl
`Multiprotocol Server (MP5)
`MPOA Guidelines
`
`Bandwidth Support on Routers
`Configurable Traffic Parameters
`
`Switched LAN Design
`Switched LAN Factors
`Broadcast Radiation
`\X/ell-behaved VLANs
`lnter~VLAN Available Bandwidth
`Administrative Boundaries
`
`Cisco VLAN Implementation Support
`IEEE 802.10
`IEEE 802.ld
`
`lnter—Switch Link (ISL)
`LAN Emulation
`Virtual Multi-homed Servers
`
`Switched LAN Topologies
`Scaled Switching
`Large Switching/Minimal Routing
`Distributed Routing/Switching
`
`Chapter 8
`
`SRB/RSRB Network Design
`
`Steps to Effective SRB Design
`Determine SRB Protocols
`
`Determine Parallel Link Requirements
`Specify an Appropriate RSRB Encapsulation Technique
`Determine \X/AN Frame Size Requirement
`
`13
`
`

`
`Contents
`
`Determine Local Acknowledgment Requirement
`Select the Appropriate IP Routing Protocol
`Explorer Packet Control
`NetBlOS Traffic Management
`Typical SRB Topologies
`Hierarchical
`Distributed
`Flat
`
`Virtual Ring Concept
`Multiport Bridging
`Redundant Star Topology
`Fully Meshed Topology
`Hierarchical Virtual Ring Topology
`Explorer Packet on Virtual Rings
`Proxy Explorer
`NetBlOS Broadcast Control
`
`NetBlOS Name Caching
`NetBlOS Datagram Broadcast
`NetBlOS Broadcast Throttling
`NetBlOS Broadcast Dampening
`Remote SRB Encapsulation Techniques
`
`_
`Direct
`TCP Encapsulation
`Fast sequenced Transport [FST) Encapsulation
`Parallel \X/AN Link issues
`
`Process Switching
`Fast Switching
`Effect of IP Routing Protocols
`Local Acknowledgment
`Design Recommendations
`IP Routing Protocols and SRB
`Link Failure Effects
`
`IGRP Network Design
`Enhanced IGRP Network Design
`OSPF Network Design
`Queuing and Prioritization
`Priority Queuing
`Custom Queuing
`SAP Prioritization
`LU Address Prioritization
`SAP Filters for WAN Links
`
`14
`
`

`
`Chapter 9
`
`DLSw+ Network Design
`DLSw Standard
`Peer Connections
`
`Exchange of Capabilities
`Circuit Establishment
`Flow Control
`Cisco DLSw+
`
`Peer Group Concept
`Explorer Firewalls
`Fault Tolerance
`Load Balancing
`Cisco DLSw+ Transport
`TCP Encapsulation
`Fast Sequenced Transport (FST)
`Direct
`DLSw Lite
`
`Encapsulation Overhead
`Cisco's Enhanced Modes of Operation
`Dual Mode
`Standard Mode
`Enhanced Mode
`
`Availability Configurations
`Load Balancing
`Redundancy
`Backup Peers
`Performance Features
`Port Lists
`Peer Groups with Border Peers and On-demand Peers
`Dynamic Peers
`
`Chapter 10 APPN Network Design
`
`Cisco Support of APPN
`Deciding Factors on Using APPN
`The Dominant Protocol is SNA
`Class of Service (COS)
`Office-to-Office Connectivity
`Non-APPN-capable SNA Resources
`Dependent Logical Unit Requester/Server
`Network Node Placement
`
`15
`
`

`
`Contents
`
`Performance Considerations
`
`Topology Database Updates
`Connection Network
`Number of CP-CP Sessions
`Number of Network Nodes
`LOCATE Search
`
`Recovery Techniques
`Secondary \X/AN Link
`Dual Routers/Dual \X/AN Links
`
`High-Performance Routing
`SSCP Takeover of DLUR
`
`Queuing and Prioritization
`APPN Buffer and Memory Management
`
`Chapter 1 I
`
`ISDN and Dial-On-Demand Routing (DDR) Design
`
`Site Options
`Central Office Switch Considerations
`PRI and BRI
`DDR Model
`DDR Dialer Cloud
`
`lP Addressing
`Topology
`Point-to-Point
`
`Hub and Spoke
`Fully Meshed
`Dial Service Considerations
`
`Data Encapsulation
`Synchronous Lines
`Asynchronous
`ISDN
`
`Dialer Rotary Groups
`Dialer Profiles
`
`Dialer Maps
`Routing Packets
`Static Routing
`Dynamic Routing
`Using Passive Interfaces
`Split Horizons
`Dynamically Connected Routes
`Snapshot Routing
`DDR as Dial Backup
`
`16
`
`

`
`Connection Triggering
`Bandwidth
`
`Interesting Packets
`Controlling Routing Updates as Triggers
`Access Lists
`
`Security
`Callback
`
`Screening
`
`Chapter 12
`
`Preparing the Cisco Router
`
`Determining the Proper IOS Code
`Locate-IOS Using Cisco Connection Online (CCO)
`CCO Software Center
`
`Downloading IOS to the TFTP Server
`Loading IOS on the Router
`Enter Privileged Mode on the Terminal Interface
`lssue Copy to/from a TFTP Server
`lssue Copy to/from the FTP Server
`Loading ClP or CPA Microcode on a Cisco 7000/7200/
`7500 Router
`
`Locating CIP/CPA Microcode on the CCO Software
`Center
`
`Enter config Parameters to Load Microcode
`Router Basic Configuration and IOS Commands
`Setting up EXEC and Privileged Mode Access
`BOOT SYSTEM List
`BOOT CONFIG List
`
`Assigning a Name to the Router
`Enabling a DNS Search and Assigning a Domain
`Specifying SNMP for Router Management ‘
`Using the Banner Command
`
`Chapter 13
`
`IP Configuration
`
`Defining Subnets on the Router Interfaces
`When to Assign Multiple IP Addresses to an Interface
`Maximizing Network Address Space Using Subnet
`Zero
`
`, Routing Same Network Packets Without a Routing
`Table Entry
`
`17
`
`

`
`Contents
`
`xix
`
`Enable IF on a Serial Interface \X/ithout Specifying
`an IP Address
`
`IP Address Mapping
`Define a Static ARP Cache
`
`Supporting Multiple ARP Encapsulation Types
`on an Interface
`
`Disable Froxy ARP
`Enabling the Use of IF Host Names in Cisco IOS
`Commands
`Static Definition of IF Host Names and IP Addresses
`Enable the Use of DNS Services
`
`Disable IP Routing
`Routing Assistance \X/hen IP Routing ls Disabled
`Bridging IP, Instead of Routing IP
`Controlling and Managing Broadcast Packets
`Enable Directed Broadcast-to-Physical Broadcast
`Translation
`
`Configure IP Services
`Disable ICMP Unreachable Messages
`Disable ICMP Redirect Messages
`Disable ICMP Mask Reply Messages
`Support for Fragmenting Large IP Packets
`Filter IP Packets Using Access Lists
`Create Standard Access Lists Using Numbers
`and Names
`Extended Access Lists
`
`Fault-Tolerant Routing of IP Packets
`IP Performance Tuning
`Compressing TCP Headers
`Enable TCP Path MTU Discovery
`Performance Enhancements Through Switching
`Features
`
`Enabling Process Switching
`Enabling Fast Switching
`Enabling Fast Switching on the Same Interface
`Enabling Autonomous Switching
`Enabling Silicon Switch Engine (SSE) Switching
`Optimum Fast Switching
`NetFlow Switching
`Distributed Switching
`
`18
`
`

`
`Defining RIP Routing Protocol
`
`The Basics of RIP
`Why Use RIP as the Routing Protocol?
`Defining RIP as a Routing Protocol on the Router
`Allow Point-to-Point (NBMA) Updates for RIP
`Specifying the Version of RIP
`Enabling RIP Version 2 Authentication
`Disable RIP Version 2 Route Summarization
`Disabling the Validation of Source IP Addresses
`Reducing Routing Loops with Split-horizon
`Tuning RIP Update Packet Delays
`RIP Updates and the Affect on Bandwidth
`
`Chapter 15 Configuring IGRP Routing Protocol
`Managing IGRP Updates and Route Advertisements
`The Holddown Algorithm for IGRP
`The Split-horizon Algorithm for IGRP
`The Poison-reverse Updates Algorithm for IGRP
`Defining IGRP as a Routing Process
`Using Unicast IGRP Routing Updates
`Increasing Throughput and Reliability Using Unequal-
`Cost Paths
`Altering IGRP Routing and Metric Computations
`Decreasing IGRP Route Convergence
`Tuning IGRP Route Convergence
`Controlling the Logical Size of an IGRP Network
`Validate Source IP Addresses
`IGRP Updates and the Affect on Bandwidth
`
`Routing ‘Protocol
`Enable EIGRP as a Routing Protocol
`I
`Migrating to EIGRP from IGRP
`Monitoring Neighbor Adjacency Changes
`Managing EIGRP Bandwidth Utilization
`Modifying EIGRP Metric Weights
`Routing Between Disconnected Networks with EIGRP
`Summarizing Routes for Advertisements out Specific
`Interfaces
`
`459
`461
`465
`467
`469.
`472
`476
`
`478
`
`19
`
`

`
`Contents
`
`Tuning Hello Packet and the Hold Time intervals
`Split-Horizon and EIGRP
`MD5 Authentication with EIGRP
`
`Chapter 17
`
`Configuring OSPF Routing Protocol
`OSPF with Cisco IOS
`
`Specifying OSPF on Cisco Routers
`Creating the OSPF Routing Process
`DR and BDR Election Using a Loopback Interface
`Multi-Area OSPF Networks
`OSPF Route Summarization
`
`Stub, Totally Stubby, and Not-So-Stubby-Area
`(NSSA) OSPF Areas
`Configuring a Stub and Totally Stubby Areas
`Configuring a NSSA
`Using OSPF Virtual Links
`Configuring Virtual Links
`Non-Broadcast and Broadcast Network Configurations
`Configuring OSPF Point-to-Multipoint
`
`Chapter 1 8
`
`Configuring BGP Routing Protocol
`
`Exterior and Interior BGP Sessions
`Path Selection Under BGP
`
`Defining the BGP Process
`Enabling the BGP Process
`Establishing BGP Peer Connections
`Forcing a Loopback Interface as the BGP Neighbor
`Multihop EBGP Connections
`Controlling Routing Information Using Route Maps
`Redistributing IGP Routes into BGP
`‘
`Nexthop Attribute and Multiaccess/NBMA Networks
`Forcing BGP to Prefer a IGP Route Using
`the Backdoor Command
`
`Synchronization of Routes
`Best Path Selection Using the Weight Attribute
`Forcing a Preferred AS Exit Path
`Influencing the Preferred Path into an AS
`Grouping Destinations That Share a Common
`Attribute
`
`Route and Path Information Filtering
`
`20
`
`

`
`Contents
`
`Manipulating the Path information Order
`Using BGP Peer Groups
`Aggregate Addresses
`Grouping Multiple Autonomous Systems into
`a BGP Confederation
`
`Reducing IBGP Peering Using Route Reflectors {RR}
`Managing Unstable Routes
`
`Chapter 19
`
`Route Redistribution
`
`Understanding Route Redistribution
`The Redistribution Router Configuration Command
`Selecting the Best Path Based on a Routing Protocol
`Altering Trusted or Believable Routes Using the
`Distance Command
`
`Modifying the Seed Metric Using the default-metric
`Command
`
`Filtering Redistributed Routes Using the distribute-
`list Command
`
`Redistribution Considerations
`Redistribution Examples
`RIP Vl—to-OSPF Redistribution
`IGRP-to-EIGRP Redistribution
`RIP-to-EIGRP Redistribution
`
`Chapter 20
`
`Defining ATM (LANE, Classical IF: and MPOA)
`
`Configuring LANE
`Initial Configuration for LANE
`Configuring a LAN Emulation Client (LEC]
`Configuring a LAN Emulation Configuration
`Server (LECS|
`Configuring a LAN Emulation Server (LES)
`Configure ATM over a Serial interface
`Configuring Classical lP
`Configuring Multiprotocol over ATM (MPOA)
`Configuring a MPOA Client (MPC)
`Configuring a MPOA Server (MP5)
`
`Chapter 21
`
`Defining Frame Relay
`
`A Simple Frame Relay Configuration
`Dynamic and Static Addressing
`
`571
`572
`574
`
`579
`582
`589
`
`593
`
`594
`595
`598
`
`598
`
`600
`
`603
`605
`606
`606
`612
`616
`
`619
`
`620
`620
`622
`
`629
`635
`638
`640
`644
`646
`649
`
`655
`
`656
`659
`
`21
`
`

`
`Contents
`
`Frame Relay Subinterfaces
`Point-to-Point Frame Relay Subinterfaces
`Multipoint Frame Relay Subinterfaces
`Specifying a Frame Relay Subinterface
`Hub and Spoke Configurations
`Dynamic Addressing for lP-Only Connectivity
`Static Addressing over a Multipoint Configuration
`Traffic Shaping on Frame Relay
`Transparent Bridging
`Managing Performance Problems Using the Broadcast
`Oueue
`
`Chapter 22
`
`Internet-working Legacy Systems
`
`Serial Tunneling (STUN)
`Source-Route Bridging Configuration
`Data Link Switching Configuration Plus (DLSw+)
`SDLC to LLC2 (SDLLC)
`Frame Relay BNN and BAN Connectivity
`APPN Support on Cisco Routers
`’
`SNA Support Using a Channel-Attached Cisco Router
`IP Connectivity Using a Channel-Attached Cisco Router
`
`Chapter 23
`
`Defining Novell Networks
`
`IPX Processing
`Configuring for IPX Routing
`Routing IPX
`IPX RIP
`
`NLSP Routing
`IPX ElGRP Routing
`IPX Static Routes
`
`IPX RouteVRedistribution
`Bridging IPX
`Transparent Bridging
`Encapsulated Bridging
`
`Chapter 24
`
`Configuring _lSDN
`
`Configuring BRI Service
`Configuring Primary Rate Interface (PRU Service
`Dial-On-Demand routing (DDR) with ISDN
`Using Caller ID
`
`22
`
`

`
`ISDN Callback
`SNAPSHOT Routing with ISDN
`Using ISDN for dial backup
`
`Appendix A
`
`Appendix B V
`
`Appendix C
`
`Appendix D
`
`Glossary
`
`Contents
`
`810
`812
`817
`
`821
`
`827
`
`831
`
`833
`
`837
`
`23
`
`

`
`About the Author
`
`George C. Sackett is Managing Director ofNetworX Corporation, a New Jer-
`sey professional services company which develops corporate data networks
`for the telecommunications, entertainment, medical, financial, and trans-
`portation industries. The author and coauthor of other McGraw—Hill titles .
`on networks, he has more than 15 years of technical and managerial expe-
`rience with corporate data networks.
`
`24
`
`

`
`25
`
`

`
`About the Reviewers
`
`As the leading publisher of technical books for more than 100 years,
`McGraw—Hill prides itself on bringing you the most authoritative and up-
`to—date information available. To ensure that our books meet the highest
`standards of accuracy, we have asked a number of top professionals and
`technical experts to review the accuracy of the material you are about to
`read.
`
`We take great pleasure in thanking the following technical reviewers
`for their insights:
`
`Jim Bender is currently with RPM Consulting, an internetworking con-
`sulting company. He has twenty—two years experience in IS/IT and has held
`positions as a mainframe Cobol/Assembler programmer, a systems pro-
`grammer supporting the operating systems and network, and Manager of
`Technical Support. He has worked with Cisco routers supporting IBM, Nov-
`ell, and Microsoft networks.
`
`E. Gary Hauser, CCIE (#4489), CCSI(#99166), CCDA, Master CNE,
`ONE 4.x, 3.x novel] is a Cisco certified systems instructor with Chesapeake
`Computer Consultants, Inc. based in San Jose, California. He currently
`teaches the BCRAN, ACRC, ICRC, and ICND courses nationwide as well as
`internal training for the Cisco SE technical staff. Recently he has been doing
`course development with Cisco for the new curriculum. He has over 11 years’
`experience in the industry, holding various positions at the Systems Engi-
`neer and Network manager levels for ADC telecommunications, SURAnet,
`and a large Washington,-D.C.-based health care provider, prior to becoming
`an Instructor/Consultant for the Annapolis, MD-based Chesapeake Com-
`puter Consultants, Inc.
`
`26
`
`

`
`Foreword
`
`i
`
`The phenomenal growth of TCP/IP and the Internet has its foundation in
`Cisco Systems routers. Cisco Systems has anywhere from 60-80% share of
`the router market. The handbook uses real world network configurations.
`Each configuration is defined, analyzed and described so that any network-
`ing professional will be able to configure a Cisco router in their network. The
`handbook explores the typical examples for router networks and explains
`in detailthe parameters most commonly used in configuring a Cisco router.
`The intended readership for this book covers a wide array of network-
`ing professionals. These include traditional networking professionals, new
`to the world of routing and experienced routing professionals needing a
`quick definitive source for configuring routers.
`Cisco routers provide not only TCP/IP network connectivity but have
`become a means for transporting many network protocols. This ability has
`made the configuration of Cisco routers convoluted and complex at times.
`The handbook guides network professionals through these complex con-
`figurations.
`
`The handbook is organized into ‘two sections. The first section covers
`network design issues for the majority of networking topologies found in
`corporate networks. The second half of the handbook discusses in detail
`the following topics:
`
`A ring, T1, ATM, Frame-Relay, ISDN.
`
`Configuring networks with routing protocols: RIP, RIP-2, IGRP, E-
`IGRP, OSPF, BGP and Novell IPX.
`
`Discussions on incorporating routers into ATM, VLANS, ELANs
`and support for Multiprotocol over ATM (MPOA).
`
`Internetworking legacy mainframe systems using RSRB, DLSw+,
`TCP/IP, Channel Interface Processors (CIP), and IBM APPN.
`
`The handbook may not cover every configuration command or address
`all the possible network topologies in use. It is the intention of this hand-
`book to become a reference for the majority of network topologies that
`every networking professional will encounter at some point in their
`career.
`
`I sincerely hope the handbook meets your expectation. You can send
`comments to me through e-mail using gsackett@networxcorp.com. I look
`forward to reading them.
`
`27
`
`

`
`CHAPTER
`
`SemmmmE0CS
`
`28
`
`

`
`Chapter 1
`
`We have all heard the saying, “It’s what’s inside that counts.” In the world
`of networking, Cisco’s Internetwork Operating Systems (IOS) has taken
`that saying to heart. The very core of Cisco Systems’ phenomenal success is
`the breadth of services provided by the Cisco IOS software.
`No two networks are exactly alike. Connectivity requirements differ
`between healthcare and manufacturing, entertainment and shipping,
`finance and telecommunications—each of which has different security
`issues. Each requires the capability to scale with reliability and manage-
`ability. The Cisco IOS software has proven to meet these criteria and to
`build on new requirements due to its flexibility in meeting the rapidly
`changing network requirements of all businesses.
`
`Benefits
`
`Cisco IOS software provides a foundation for meeting all the current and
`future networking requirements found in todafs complex services-driven
`business environments. Businesses rely heavily on generating income from
`their network infrastructure. Cisco IOS software has the broadest set of
`
`networking features primarily based on international standards allowing
`Cisco products to interoperate with disparate media and devices across an
`enterprise network. Most importantly, Cisco IOS software enables corpora-
`tions to deliver mission-critical applications seamlessly between various
`computing and networking systems.
`
`Scalability
`
`The network infrastructure for every corporation must be flexible to meet
`all the current and future internetworking requirements. Cisco IOS soft-
`ware uses some proprietary‘ but also adheres to international standards for
`congestion avoidance using scalable routing protocols. These routing proto-
`cols allow a network using Cisco IOS to overcome network protocol limita-
`tions and deficiencies inherent in the protocols’ architectures. Additional
`features in scaling an efficient use of bandwidthand resources include the
`
`ability of the IOS software in detailed packet filtering for reducing “chatty”
`protocol traffic as well as reducing network broadcasts through timers and
`helper addresses. All these features and more are available with the goal of
`reducing network traffic overhead, thereby maintaining an efficient yet
`effective network infrastructure.
`
`29
`
`

`
`Cisco IOS Software
`
`Adaptiveness
`
`Network outages occur frequently in corporate networks. However, these
`outages do not often affect the flow of business due to the reliability and
`adaptiveness of the policy—based IOS software routing features. Using rout-
`ing protocols, each Cisco router can dynamically decide on the best route for
`delivering packets through the network around outages, thereby providing
`reliable delivery of information. The prioritization of packets and services
`enables Cisco routers to adapt to bandwidth constraints due to outages or
`high bandwidth utilization. IOS software load~balances traffic throughput
`over various network connections, preserving bandwidth and maintaining
`network performance.
`The concept of virtual local area networks (LANS) has become a reality
`for many corporate networks. Cisco routers have the capability to partici-
`pate in these virtual LANs using emulated LAN functions for physical LAN
`extensions and ATM LAN Emulation (LANE) services. These are just two
`of the many newer networking technologies incorporated into the IOS soft-
`ware feature set, enabling networks to implement newer technologies with-
`out the added expense of new hardware.
`
`Access Support
`
`The Cisco IOS software access support encompasses remote access and pro-
`tocol translation services. These services provide connectivity to
`
`Terminals
`
`L*%=i:% Modems
`
`::::a Computers
`sag Printers
`
`Workstations
`
`Various network configurations exist for connecting these network
`resources over LANs and wide area networks (WANs). LAN terminal ser-
`vice support is as follows:
`
`TCP/IP support for Telnet and rlogin connections to IP hosts.
`TN3270 connections to IBM hosts.
`
`is LAT connections to DEC hosts.
`
`30
`
`

`
`Chapter 1
`
`For WANs, Cisco IOS software supports four flavors of server operations:
`
`Connectivity over a dial—up connection supporting
`AppleTalk Remote Access (ARA)
`*1 Serial Line Internet Protocol (SLIP)
`
`N Compressed SLIP (CSLIP)
`Point—to—Point Protocol (PPP)
`~ Xremote, Network Computing Dev1'ce’s (NCD) X Window System
`terminal protocol
`iii Asynchronous terminal connectivity to a LAN or WAN using network
`and terminal emulation software supporting Telnet, rlogin, DEC’s
`Local Area Transport (LAT) protocol, and IBM TN3270 terminal
`protocol.
`Conversion of a virtual terminal protocol into another protocol, such as
`LAT-TCP or TCP-LAT communication between a terminal and a host
`computer over the network.
`33;: Support for full Internet Protocol (IP), Novell Internet Packet
`Exchange (IPX), and AppleTalk routing over dial-up asynchronous
`connections.
`
`Performance Optimization
`
`Optimizing networks requires network equipment to dynamically make
`decisions on routing packets in a cost-effective manner over the network.
`Cisco IOS software has two features that can greatly enhance bandwidth
`management, recovery, and routing in the network. These two features are
`dial-on-demand access (DDA) and dial-on-demand routing (DDR).
`DDA is useful in several scenarios. Those are
`
`l‘-iii Dial backup
`
`Dynamic bandwidth
`In many instances, connectivity to a location fails because of a modem,
`DSU/CSU failure, or the main telecommunications line to the office is dis-
`rupted in some way. A good network design has a backup solution for this
`type of outage. Using DDA, a router can sense the line outage and perform
`a dial backup connection over a switched serial, ISDN, T1, or frame relay. In
`this manner, the office maintains connectivity to the \WAN with minimal
`
`31
`
`

`
`Cisco IOS Software
`
`5
`
`downtime. The DDA function monitors the primary line for activation and
`can cut back to the primary connection automatically if so desired.
`DDA features the capability to determine a low and high bandwidth
`watermark on the permanent lines. This feature allows the addition of a
`temporary bandwidth to another location to meet throughput and perfor-
`mance criteria. The IOS monitors the permanent line for high bandwidth
`utilization. If the bandwidth reaches the defined threshold, DDA is enabled
`to add extra bandwidth to the remote location of the permanent line. IOS
`continues to monitor the bandwidth for utilization to fall under the thresh-
`old for a period of time. Once the low watermark is reached, IOS discon-
`nects the DDA line. Using DDA in this fashion enables the IOS to maintain
`performance criteria between the two locations.
`DDR allows Cisco routers to create temporary WAN connections based
`on interesting packets. IP, Novell IPX, X.25, Frame Relay, and SMDS desti-
`nation addresses can be specified under DDR as interesting packets. Once
`th