JNCIA Study Guide - Juniper Networks

628 Pages·2002·6.01 MB·English

by  Juniper Networks, Inc.

JNCIA
Juniper Networks
™
Certified Internet Associate
Study Guide
by Joseph M. Soricelli
with John L. Hammond, Galina Diker Pildush,
Thomas E. Van Meter, and Todd M. Warble
This book was originally developed by Juniper Networks Inc. in conjunction with
Sybex Inc. It is being offered in electronic format because the original book
(ISBN: 0-7821-4071-8) is now out of print. Every effort has been made to remove
the original publisher's name and references to the original bound book and its
accompanying CD. The original paper book may still be available in used book
stores or by contacting, John Wiley & Sons, Publishers. www.wiley.com.
Copyright © 2003-6 by Juniper Networks Inc. All rights reserved.
This publication may be used in assisting students to prepare for a Juniper
JNCIA exam but Juniper Networks Inc. cannot warrant that use of this
publication will ensure passing the relevant exam.
Contents at a Glance
Introduction xvii
Assessment Test xxxiii
Chapter 1 The Components of a Juniper Networks Router 1
Chapter 2 Interfaces 61
Chapter 3 Protocol-Independent Routing 107
Chapter 4 Routing Policy 149
Chapter 5 The Routing Information Protocol (RIP) 195
Chapter 6 Open Shortest Path First (OSPF) 229
Chapter 7 Intermediate System to Intermediate System (IS-IS) 275
Chapter 8 Border Gateway Protocol (BGP) 321
Chapter 9 Multicast 373
Chapter 10 Firewall Filters 429
Chapter 11 Multiprotocol Label Switching (MPLS) 473
Glossary 533
Index 569
Contents
Introduction xvii
Assessment Test xxxiii
Chapter 1 The Components of a Juniper Networks Router 1
Juniper Networks Router Design 2
Routing Engine Overview 3
Packet Forwarding Engine Overview 4
Routing Engine Components 6
Software Architecture 6
Command-Line Interface 13
Manipulating Files on the Router 44
Routing Engine Redundancy 46
Packet Forwarding Engine Components 47
Embedded OS Software 47
Application-Specific Integrated Circuits 47
Packet Flow 49
Summary 52
Exam Essentials 52
Key Terms 54
Review Questions 55
Answers to Review Questions 59
Chapter 2 Interfaces 61
Types of Interfaces 62
Permanent Interfaces 62
Transient Interfaces 63
Interface Naming 63
Interface Naming Structure 64
Interface Naming Examples 67
Interface Properties 68
Physical Properties 68
Logical Properties 70
Disabling or Deactivating an Interface 73
Configuration Examples 74
IP Version 4 75
IPv6 Support 80
IS-IS Support 82
MPLS Support 84
Useful Interface Commands 85
show interfaces extensive 85
iv
monitor interface 88
monitor traffic 89
show arp 90
ping 90
ping atm 91
traceroute 91
Contents
Interface Diagnostic Commands 92
Loopback Testing 93
BERT Testing 96
Summary 98
Exam Essentials 98
Key Terms 99
Review Questions 100
Answers to Review Questions 104
Chapter 3 Protocol-Independent Routing 107
Configured Routes 108
Static Routes 108
Aggregated Routes 116
Generated Routes 121
Martian Routes 126
JUNOS software Implementation 127
Configuration Examples 127
JUNOS software Routing Tables 131
Table inet.0 131
Table inet.1 132
Table inet.2 133
Table inet.3 133
Table inet.4 134
Table inet6.0 134
Table mpls.0 134
Table bgp.l3vpn.0 135
Table bgp.l2vpn.0 135
JUNOS software Preference Values 136
Load Balancing 137
Summary 140
Exam Essentials 140
Key Terms 141
Review Questions 142
Answers to Review Questions 147
Chapter 4 Routing Policy 149
What Is a Routing Policy? 150
The Routing Table 150
Contents v
Why Modify the Routing Table? 151
Changing the Map 153
Forming a Policy 153
Composing a Routing Policy 153
Match Conditions 157
Actions 169
Default Policy 171
Applying Routing Policies 173
RIP Policy Application 173
Link-State IGP Policy Application 174
BGP Policy Application 174
Useful JUNOS software Commands 176
Configuring Multiple Policies 177
insert 177
rename 178
show route Options 180
Summary 183
Exam Essentials 184
Key Terms 185
Review Questions 186
Answers to Review Questions 192
Chapter 5 The Routing Information Protocol (RIP) 195
Overview of RIP 196
RIP Features 197
RIP Operations 199
Input Processing 199
Output Processing 201
Stability Features 201
Timers 203
Limitations 205
Packet Types 206
Version 1 Packet Format 207
Version 2 Packet Format 208
RIPv2 Extensions 209
JUNOS software Configuration 210
Minimum RIP Configuration 210
Applying Export Policy 212
Applying Import Policy 214
Modifying the Incoming Metric 215
Modifying the Outgoing Metric 216
Configuring Authentication 216
Controlling Route Preference 217
Configuring Update Messages 218
vi
Configuring the Number of Route Entries in an Update
Message 220
Accepting Packets Whose Reserved Fields Are Nonzero 220
Summary 221
Exam Essentials 221
Key Terms 222
Contents
Review Questions 223
Answers to Review Questions 227
Chapter 6 Open Shortest Path First (OSPF) 229
Basic OSPF Operation 230
Link-State Protocol Review 230
Packet Types 232
Forming Adjacencies 238
Evolution of an OSPF Network 242
The Router LSA 242
Broadcast Networks 243
Scaling an OSPF Network 246
Non-OSPF Routes 250
Additional Scaling Techniques 252
OSPF Configuration 255
Single OSPF Area 255
Multiple OSPF Areas 258
JUNOS software Commands 259
Troubleshooting Your Configuration 259
Troubleshooting the Routing Protocol 261
Summary 266
Exam Essentials 267
Key Terms 268
Review Questions 269
Answers to Review Questions 273
Chapter 7 Intermediate System to Intermediate System (IS-IS) 275
Overview of IS-IS 276
Link-State Review 277
IS-IS Levels 278
Addressing 282
Protocol Specifics 284
IS-IS Adjacency States 284
General IS-IS Information Exchange 284
Protocol Data Units 285
Command-Line Interface 298
Configuration Commands 298
Verification and Troubleshooting Commands 303
Contents vii
Comparison to OSPF 311
Summary 312
Exam Essentials 312
Key Terms 313
Review Questions 314
Answers to Review Questions 318
Chapter 8 Border Gateway Protocol (BGP) 321
Overview of BGP 322
Network Connectivity 322
Policy Control 323
Reliable Transport 324
Routing Table Scalability 325
Theory of Operation 326
Peers 327
Establishing Relationships 332
Message Types 333
Routing Information Bases 337
The Route Selection Process 338
BGP Attributes 339
Juniper Networks Implementation 345
Establishing Peer Relationships 346
Viewing Routing Knowledge 353
Solving Next Hop Reachability 357
Summary 365
Exam Essentials 365
Key Terms 366
Review Questions 367
Answers to Review Questions 371
Chapter 9 Multicast 373
Multicast Overview 374
Unicast Transmissions 375
Broadcast Transmissions 376
Multicast Transmissions 377
Multicast Addressing 377
IP Group Addresses 378
Ethernet Addresses 380
Multicast Forwarding 383
Reverse Path Forwarding 383
Dense-Mode Forwarding 386
Sparse-Mode Forwarding 388
viii
Multicast Protocols 390
Internet Group Management Protocol 390
Protocol Independent Multicast 393
JUNOS software Commands 403
IGMP Configuration 404
PIM Configuration 406
Contents
show pim neighbors 417
show pim join extensive 418
show pim source 418
show multicast rpf 419
show multicast route 420
show route table inet.1 420
show multicast usage 420
Summary 421
Exam Essentials 421
Key Terms 422
Review Questions 423
Answers to Review Questions 427
Chapter 10 Firewall Filters 429
Firewall Filter Overview 430
Implementing a Firewall Filter 431
Writing the Firewall Filter 431
Processing Filters 432
Segmenting Filters 433
The Default Action 434
Match Conditions 434
Actions 446
Applying Firewall Filters 452
Protecting the Routing Engine 453
Rate Policing 455
Rate Limits 455
Filter Policers 456
Interface Policers 458
JUNOS software Commands 459
show firewall 460
show firewall log 460
show log messages 461
clear firewall 462
show interfaces filters 462
show interfaces policers 462
show policer 463
insert 463
rename 464
Contents ix
Summary 464
Exam Essentials 465
Key Terms 465
Review Questions 466
Answers to Review Questions 470
Chapter 11 Multiprotocol Label Switching (MPLS) 473
The Creation of MPLS 474
The History of Traffic Engineering and MPLS 475
IP Routing 475
ATM and Overlay Networks 476
SONET and MPLS 478
MPLS Operations 480
Terminology 480
Packet Processing 485
Establishing an LSP 486
Signaling Protocols 488
MPLS Implementation 493
Configuring a Static LSP 494
Configuring a Dynamic LSP 500
Altering the RSVP Protocol 510
Routing Table Integration 516
Summary 524
Exam Essentials 525
Key Terms 526
Review Questions 527
Answers to Review Questions 531
Glossary 533
Index 569
Introduction
Greetings and welcome to the world of Juniper Networks. This introductory section serves as a loca-
tion to pass on to you some pertinent information concerning the Juniper Networks Technical Cer-
tification Program. In addition, you’ll find information about how the book itself is laid out and
what it contains. Finally, we’ll review some technical information that you should already know
before reading this book.
Juniper Networks Technical Certification Program
The Juniper Networks Technical Certification Program (JNTCP) consists of two platform-
specific, multitiered tracks. Each exam track allows participants to demonstrate their compe-
tence with Juniper Networks technology through a combination of written proficiency and
hands-on configuration exams. Successful candidates demonstrate a thorough understanding of
Internet technology and Juniper Networks platform configuration and troubleshooting skills.
The two JNTCP tracks focus on the M-series Routers & T-series Routing Platforms and the
ERX Edge Routers, respectively. While some Juniper Networks customers and partners work
with both platform families, it is most common to find individuals working with only one or the
other platform. The two different certification tracks allow candidates to pursue specialized cer-
tifications, which focus on the platform type most pertinent to their job functions and experi-
ence. Candidates wishing to attain a certification on both platform families are welcome to do
so, but are required to pass the exams from each track for their desired certification level.
This book covers the M-series & T-series track. For information on the ERX
Edge Routers certification track, please visit the JNTCP website at http://
www.juniper.net/certification.
M-series Routers & T-series Routing Platforms
The M-series Routers certification track consists of four tiers. They include the following:
Juniper Networks Certified Internet Associate (JNCIA) The Juniper Networks Certified
Internet Associate, M-series, T-series Routers (JNCIA-M) certification does not have any
prerequisites. It is administered at Prometric testing centers worldwide.
Juniper Networks Certified Internet Specialist (JNCIS) The Juniper Networks Certified
Internet Specialist, M-series, T-series Routers (JNCIS-M) certification also does not have any
prerequisites. Like the JNCIA-M, it is administered at Prometric testing centers worldwide.
Juniper Networks Certified Internet Professional (JNCIP) The Juniper Networks Certified
Internet Professional, M-series, T-series Routers (JNCIP-M) certification requires that candi-
dates first obtain the JNCIS-M certification. The hands-on exam is administered at Juniper Net-
works offices in select locations throughout the world.
Juniper Networks Certified Internet Expert (JNCIE) The Juniper Networks Certified Inter-
net Expert, M-series, T-series Routers (JNCIE-M) certification requires that candidates first