H3C S9500E Series User manual

H3C S9500E Series Routing Switches
Layer3 - IP Routing Configuration Guide
Hangzhou H3C Technologies Co., Ltd.
http://www.h3c.com
Document Version:
Product Version:

Copyright © 2003-2010, Hangzhou H3C Technologies Co., Ltd. and its licensors
All Rights Reserved
No part of this manual may be reproduced or transmitted in any form or by any means without prior
written consent of Hangzhou H3C Technologies Co., Ltd.
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H3C, , Aolynk, , H3Care, , TOP G, , IRF, NetPilot, Neocean, NeoVTL,
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XGbus, N-Bus, TiGem, InnoVision and HUASAN are trademarks of Hangzhou H3C Technologies Co.,
Ltd.
All other trademarks that may be mentioned in this manual are the property of their respective owners.
Notice
The information in this document is subject to change without notice. Every effort has been made in the
preparation of this document to ensure accuracy of the contents, but all statements, information, and
recommendations in this document do not constitute the warranty of any kind, express or implied.
Environmental Protection
This product has been designed to comply with the requirements on environmental protection. The
storage, use, and disposal of this product must meet the applicable national laws and regulations.

Preface
The H3C S9500E documentation set includes 13 configuration guides, which describe the software
features for the H3C S9500E Series Routing Switches and guide you through the software configuration
procedures. These configuration guides also provide configuration examples to help you apply software
features to different network scenarios.
This preface includes:
•Audience
•Conventions
•About the H3C S9500E Documentation Set
•Obtaining Documentation
•Documentation Feedback
Audience
This documentation is intended for:
Network planners
Field technical support and servicing engineers
Network administrators working with the S9500E series

4
Conventions
This section describes the conventions used in this documentation set.
Command conventions
Convention Description
Boldface Bold text represents commands and keywords that you enter literally as shown.
italic Italic text represents arguments that you replace with actual values.
[ ] Square brackets enclose syntax choices (keywords or arguments) that are
optional.
{ x | y | ... }
Braces enclose a set of required syntax choices separated by vertical bars, from
which you select one.
[ x | y | ... ]
Square brackets enclose a set of optional syntax choices separated by vertical
bars, from which you select one or none.
{ x | y | ... } *
Asterisk marked braces enclose a set of required syntax choices separated by
vertical bars, from which you select at least one.
[ x | y | ... ] *
Asterisk marked square brackets enclose optional syntax choices separated by
vertical bars, from which you may select multiple choices or none.
&<1-n> The argument or keyword and argument combination before the ampersand (&)
sign can be entered 1 to n times.
# A line that starts with a pound (#) sign is comments.
GUI conventions
Convention Description
< > Button names are inside angle brackets. For example, click <OK>.
[ ] Window names, menu items, data table and field names are inside square
brackets. For example, pop up the [New User] window.
/ Multi-level menus are separated by forward slashes. For example,
[File/Create/Folder].
Symbols
Convention Description
Means reader be extremely careful. Improper operation may cause bodily
injury.
Means reader be careful. Improper operation may cause data loss or damage
to equipment.
Means an action or information that needs special attention to ensure successful
configuration or good performance.
Means a complementary description.
Means techniques helpful for you to make configuration with ease.

5
Network topology icons
Convention Description
Represents a generic network device, such as a router, switch, or firewall.
Represents a routing-capable device, such as a router or Layer 3 switch.
Represents a generic switch, such as a Layer 2 or Layer 3 switch, or a router
that supports Layer 2 forwarding and other Layer 2 features.

6
About the H3C S9500E Documentation Set
The H3C S9500E documentation set includes:
Category Documents Purposes
Product description and
specifications
Marketing brochures Describe product specifications and benefits.
Technology white papers Provide an in-depth description of software features
and technologies.
Card datasheets Describe card specifications, features, and standards.
Hardware specifications
and installation
Compliance and safety
manual
Provides regulatory information and the safety
instructions that must be followed during installation.
Quick start
Guides you through initial installation and setup
procedures to help you quickly set up and use your
device with the minimum configuration.
Installation guide Provides a complete guide to hardware installation
and hardware specifications.
Card manuals Provide the hardware specifications of cards.
H3C N68 Cabinet
Installation and Remodel
Introduction
Guides you through installing and remodeling H3C
N68 cabinets.
H3C Pluggable SFP
[SFP+][XFP] Transceiver
Modules Installation
Guide
Guides you through installing SFP/SFP+/XFP
transceiver modules.
Adjustable Slider Rail
Installation Guide
Guides you through installing adjustable slider rails to
a rack.
H3C High-End Network
Products Hot-Swappable
Module Manual
Describes the hot-swappable modules available for the
H3C high-end network products, their external views,
and specifications.
Installation videos Show how to install the LSTM1PEMC and
LSTM1PEM2N AC-input power supply modules.
Software configuration
Configuration guides Describe software features and configuration
procedures.
Command references Provide a quick reference to all available commands.
Configuration examples Describe typical network scenarios and provide
configuration examples and instructions.
Operations and
maintenance
System log messages Explains the system log messages.
Trap messages Explains the trap messages.
MIB Companion Describes the MIBs for the software release.
Release notes
Provide information about the product release,
including the version history, hardware and software
compatibility matrix, version upgrade information,
technical support information, and software
upgrading.

7
Category Documents Purposes
Error code reference Explains the error codes for the QoS module.

8
Obtaining documentation
You can access the most up-to-date H3C product documentation on the World Wide Web at
http://www.h3c.com.
Click the links on the top navigation bar to obtain different categories of product documentation:
[Technical Support & Documents > Technical Documents] – Provides hardware installation, software
upgrading, and software feature configuration and maintenance documentation.
[Products & Solutions] – Provides information about products and technologies, as well as solutions.
[Technical Support & Documents > Software Download] – Provides the documentation released with the
software version.
Documentation feedback
You can e-mail your comments about product documentation to [email protected].
We appreciate your comments.

9
Table of Contents
Preface ·········································································································································································· 3
Audience············································································································································································3
Conventions ·······································································································································································4
About the H3C S9500E Documentation Set··················································································································6
IP routing basics configuration··································································································································20
IP routing and routing table ·········································································································································· 20
Routing···································································································································································· 20
Routing table·························································································································································· 20
Routing protocol overview············································································································································· 22
Static routing and dynamic routing ····················································································································· 22
Dynamic routing protocols classification ············································································································ 22
Routing protocols and routing preference ·········································································································· 23
Load balancing and route backup ······················································································································ 24
Route recursion ······················································································································································ 24
Routing information sharing ································································································································· 24
Configuring a router ID ················································································································································· 24
Displaying and maintaining a routing table ··············································································································· 25
Static routing configuration ·······································································································································27
Static route ····························································································································································· 27
Default route··························································································································································· 27
Application environment······································································································································· 27
Configuring a static route·············································································································································· 28
Configuring BFD for static routes························································································································· 29
Configuring static route FRR·········································································································································· 31
Displaying and maintaining static routes ···················································································································· 32
Static route configuration examples····························································································································· 33
Basic static route configuration example ············································································································ 33
Static route FRR configuration example ·············································································································· 35
Configuring BFD echo packet mode ··················································································································· 38
Configuring BFD control packet mode for static routing··················································································· 40
RIP configuration ························································································································································42
RIP overview ··································································································································································· 42
RIP routing table ···················································································································································· 42
RIP timers ································································································································································ 42
Routing loops prevention ······································································································································ 43
Operating RIP ························································································································································ 43
RIP versions ···························································································································································· 43
RIP message format ··············································································································································· 44

10
Supported RIP features·········································································································································· 46
Protocols and standards ······································································································································· 46
Configuring RIP basic functions ···································································································································· 46
Configuring RIP route control········································································································································ 48
Configuring an additional routing metric ··········································································································· 49
Configuring RIPv2 route summarization·············································································································· 49
Disabling host route reception ····························································································································· 50
Advertising a default route ··································································································································· 51
Configuring inbound or outbound route filtering······························································································· 52
Configuring a priority for RIP······························································································································· 52
Configuring RIP route redistribution····················································································································· 53
Configuring RIP network optimization ························································································································· 53
Configuring RIP timers··········································································································································· 53
Configuring split horizon and poison reverse···································································································· 54
Configuring the maximum number of load balanced routes············································································ 55
Enabling zero field check on incoming RIPv1 messages ·················································································· 55
Enabling source IP address check on incoming RIP updates············································································ 56
Configuring RIPv2 message authentication ········································································································ 56
Specifying a RIP neighbor ···································································································································· 57
Configuring RIP-to-MIB binding···························································································································· 57
Configuring the RIP packet sending rate ············································································································ 57
Configuring RIP FRR ·············································································································································· 58
Configuring BFD for RIP················································································································································· 59
Single-hop detection in BFD echo packet mode ································································································ 59
Bidirectional detection in BFD control packet mode·························································································· 60
Displaying and maintaining RIP ··································································································································· 60
RIP configuration examples··········································································································································· 61
Configuring RIP version ········································································································································ 61
Configuring RIP route redistribution····················································································································· 63
Configuring an additional metric for a RIP interface························································································· 65
Configuring RIP to advertise a summary route··································································································· 67
RIP FRR configuration example ···························································································································· 70
Configuring BFD for RIP (single-hop detection in BFD echo packet mode) ····················································· 72
Configuring BFD for RIP (bidirectional detection in BFD control packet mode)·············································· 75
Troubleshooting RIP························································································································································ 79
No RIP updates received ······································································································································ 79
Route oscillation occurred ···································································································································· 79
OSPF configuration····················································································································································80
Introduction to OSPF······················································································································································ 80
Basic concepts ······················································································································································· 80
OSPF area partition ·············································································································································· 82
Router types···························································································································································· 86
Classification of OSPF networks ·························································································································· 87

11
DR and BDR ··························································································································································· 88
OSPF packet formats············································································································································· 89
Supported OSPF features ····································································································································· 99
Protocols and standards ·····································································································································101
OSPF configuration tasks ············································································································································101
Enabling OSPF ·····························································································································································102
Prerequisites ·························································································································································102
Configuration procedure ····································································································································102
Configuring OSPF areas ·············································································································································103
Prerequisites ·························································································································································103
Configuring a stub area ·····································································································································104
Configuring an NSSA area································································································································104
Configuring a virtual link····································································································································105
Configuring OSPF network types ·······························································································································106
Prerequisites ·························································································································································106
Configuring the OSPF network type for an interface as broadcast·······························································107
Configuring the OSPF network type for an interface as NBMA ····································································107
Configuring the OSPF network type for an interface as P2MP ······································································108
Configuring the OSPF network type for an interface as P2P··········································································109
Configuring OSPF route control ·································································································································110
Prerequisites ·························································································································································110
Configuring OSPF route summarization ···········································································································110
Configuring OSPF inbound route filtering ········································································································112
Configuring ABR Type-3 LSA filtering ···············································································································112
Configuring an OSPF cost for an interface ······································································································113
Configuring the maximum number of OSPF routes ·························································································114
Configuring the maximum number of load-balanced routes ··········································································114
Configuring a priority for OSPF·························································································································114
Configuring OSPF route redistribution ··············································································································115
Advertising a host route······································································································································117
Configuring OSPF network optimization···················································································································117
Prerequisites ·························································································································································117
Configuring OSPF packet timers························································································································117
Specifying an LSA transmission delay ··············································································································118
Specifying SPF calculation interval····················································································································119
Specifying the LSA minimum repeat arrival interval························································································119
Specifying the LSA generation interval ·············································································································120
Disabling interfaces from receiving or sending OSPF packets·······································································121
Configuring stub routers ·····································································································································121
Configuring OSPF authentication ······················································································································122
Adding the interface MTU into DD packets······································································································123
Configuring the maximum number of external LSAs in LSDB ·········································································123
Making external route selection rules defined in RFC 1583 compatible······················································124
Logging neighbor state changes························································································································124

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Configuring OSPF network management ·········································································································124
Enabling message logging·································································································································125
Enabling the advertisement and reception of opaque LSAs ···········································································126
Configuring OSPF to give priority to receiving and processing hello packets·············································126
Configuring the LSU transmit rate······················································································································126
Configuring OSPF FRR········································································································································127
Prerequisites ·························································································································································128
Configure OSPF FRR to automatically calculate a backup next hop ·····························································128
Configure OSPF FRR to designate a backup next hop using a routing policy ·············································128
Configuring OSPF graceful restart ·····························································································································129
Configuring the OSPF GR Helper······················································································································130
Triggering OSPF Graceful Restart······················································································································131
Configuring BFD for OSPF ··········································································································································131
Displaying and maintaining OSPF·····························································································································132
OSPF configuration examples ····································································································································134
Configuring OSPF basic functions·····················································································································134
Configuring OSPF route redistribution ··············································································································138
Configuring OSPF to advertise a summary route·····························································································140
Configuring an OSPF stub area·························································································································143
Configuring an OSPF NSSA area·····················································································································147
Configuring OSPF DR election···························································································································149
Configuring OSPF virtual links ···························································································································154
OSPF Graceful Restart configuration example·································································································156
Configuring route filtering ··································································································································158
Configuring OSPF FRR········································································································································161
Configuring BFD for OSPF ·································································································································163
Troubleshooting OSPF configuration ·························································································································165
No OSPF neighbor relationship established ····································································································165
Incorrect routing information ······························································································································165
IS-IS configuration ··················································································································································· 167
IS-IS overview ·······························································································································································167
Basic concepts ·····················································································································································167
IS-IS area ······························································································································································169
IS-IS network types ··············································································································································171
IS-IS PDU format···················································································································································173
Supported IS-IS features······································································································································179
Protocols and standards ·····································································································································182
IS-IS configuration tasks···············································································································································182
Configuring IS-IS basic functions ·······················································································································182
Enabling IS-IS·······················································································································································183
Configuring the IS level and circuit level ··········································································································183
Configuring the network type of an interface as P2P······················································································184
Configuring IS-IS routing information control············································································································184

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Configuring IS-IS link cost···································································································································184
Specifying a priority for IS-IS ·····························································································································186
Configuring the maximum number of equal-cost routes··················································································187
Configuring IS-IS route summarization··············································································································187
Advertising a default route ·································································································································188
Configuring IS-IS route redistribution ················································································································188
Configuring IS-IS route filtering··························································································································189
Configuring IS-IS route leaking ··························································································································190
Tuning and optimizing IS-IS networks························································································································191
Specifying intervals for sending IS-IS hello and CSNP packets ·····································································191
Specifying the IS-IS hello multiplier····················································································································191
Configuring a DIS priority for an interface·······································································································192
Disabling an interface from sending or receiving IS-IS packets ·····································································192
Enabling an interface to send small hello packets···························································································193
Configuring LSP parameters·······························································································································193
Configuring SPF parameters ······························································································································197
Setting the LSDB overload bit·····························································································································197
Configuring IS-IS authentication ·································································································································198
Configuring neighbor relationship authentication ···························································································198
Configuring area authentication························································································································198
Configuring routing domain authentication······································································································199
Configuring system ID to host name mappings ········································································································199
Configuring a static system ID to host name mapping····················································································200
Configuring dynamic system ID to host name mapping ·················································································200
Configuring IS-IS GR····················································································································································201
Configuring IS-IS NSR··················································································································································202
Configuring IS-IS FRR ···················································································································································203
Introduction ··························································································································································203
Configure IS-IS FRR to automatically calculate a backup next hop································································204
Configure IS-IS FRR to designate a backup next hop with a routing policy··················································204
Enabling the logging of neighbor state changes······································································································205
Enabling IS-IS SNMP trap ···········································································································································205
Binding an IS-IS process with MIBs ····························································································································205
Configuring BFD for IS-IS·············································································································································206
Displaying and maintaining IS-IS ·······························································································································206
IS-IS configuration examples·······································································································································207
IS-IS basic configuration ·····································································································································207
DIS election configuration ··································································································································213
Configuring IS-IS route redistribution ················································································································218
IS-IS-based Graceful Restart configuration example························································································223
IS-IS NSR configuration example·······················································································································225
IS-IS FRR configuration example ························································································································228
IS-IS authentication configuration example·······································································································231
Configuring BFD for IS-IS····································································································································233

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BGP configuration··················································································································································· 236
BGP overview ·······························································································································································236
Formats of BGP messages ··································································································································237
BGP path attributes ·············································································································································240
BGP route selection ·············································································································································244
iBGP and IGP synchronization ··························································································································246
Settlements for problems in large-scale BGP networks····················································································247
BGP GR ································································································································································251
MP-BGP·································································································································································252
Protocols and standards ·····································································································································253
BGP configuration························································································································································253
Configuring BGP connection······························································································································253
Creating a BGP connection································································································································253
Specifying the source interface for TCP connections·······················································································254
Allowing establishment of eBGP connection to a non-directly connected peer or peer group ······················255
Controlling route distribution and reception ·············································································································256
Configuring BGP route redistribution ················································································································256
Configuring BGP route summarization ·············································································································256
Advertising a default route to a peer or peer group ·······················································································257
Configuring BGP route distribution filtering policies ·······················································································257
Configuring BGP route reception filtering policies ··························································································258
Enabling BGP and IGP route synchronization ·································································································259
Configuring BGP route dampening···················································································································260
Configuring BGP route attributes································································································································260
Tuning and optimizing BGP networks························································································································262
Configuring BGP keepalive interval and holdtime ··························································································262
Configuring the interval for sending the same update····················································································263
Configuring BGP soft-reset··································································································································263
Enabling the BGP ORF capability······················································································································265
Enabling quick eBGP session reestablishment ·································································································266
Enabling MD5 authentication for TCP connections ·························································································266
Configuring BGP load balancing ······················································································································266
Forbiding session establishment with a peer or peer group···········································································267
Configuring a large-scale BGP network ····················································································································267
Configuring BGP peer groups ···························································································································267
Configuring BGP community······························································································································270
Configuring a BGP route reflector·····················································································································270
Configuring a BGP confederation ·····················································································································271
Configuring BGP GR ···················································································································································271
Enabling trap································································································································································272
Configuring BFD for BGP ············································································································································273
Displaying and maintaining BGP·······························································································································273
Displaying BGP····················································································································································273
Resetting BGP connections ·································································································································275

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Clearing BGP information ··································································································································275
BGP configuration examples ······································································································································275
BGP basic configuration·····································································································································276
BGP and IGP synchronization configuration····································································································281
BGP load balancing configuration····················································································································284
BGP community configuration····························································································································286
BGP route reflector configuration ······················································································································289
BGP confederation configuration ······················································································································291
BGP path selection configuration ······················································································································295
Configuring BFD for BGP ···································································································································299
BGP GR configuration·········································································································································302
Troubleshooting BGP ···················································································································································303
No BGP peer relationship established··············································································································303
IP unicast policy routing configuration ·················································································································· 305
Introduction to IP unicast policy routing·····················································································································305
Policy routing ·······················································································································································305
Track-policy routing collaboration ·····················································································································305
Configuring IP unicast policy routing·························································································································306
Defining a policy ·················································································································································306
Configuring local policy routing························································································································307
Configuring interface policy routing ·················································································································307
Displaying and maintaining IP unicast policy routing configuration ······································································308
IP unicast policy routing configuration examples ·····································································································308
Configuring local policy routing based on packet type··················································································308
Configuring interface policy routing based on packet type ···········································································311
IPv6 static routing configuration····························································································································· 313
Introduction to IPv6 static routing ·······························································································································313
Features of IPv6 static routes ······························································································································313
Default IPv6 route ················································································································································313
Configuring an IPv6 static route ·································································································································313
Configuring an IPv6 static route ························································································································313
Displaying and maintaining IPv6 static routes··········································································································314
IPv6 static routing configuration example ·················································································································314
RIPng configuration················································································································································· 324
Introduction to RIPng····················································································································································324
RIPng working mechanism··································································································································325
RIPng packet format ············································································································································325
RIPng packet processing procedure ··················································································································327
Protocols and standards ·····································································································································327
Configuring RIPng basic functions······························································································································327
Configuring RIPng route control ·································································································································328
Configuring an additional routing metri ···········································································································328

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Configuring RIPng route summarization ···········································································································329
Advertising a default route ·································································································································329
Configuring a RIPng route filtering policy·········································································································329
Configuring a priority for RIPng·························································································································330
Configuring RIPng route redistribution ··············································································································330
Tuning and optimizing the RIPng network·················································································································331
Configuring RIPng timers ····································································································································331
Configuring split horizon and poison reverse··································································································331
Configuring zero field check on RIPng packets ·······························································································332
Configuring the maximum number of equal cost routes for load balancing ················································333
Displaying and maintaining RIPng·····························································································································333
RIPng configuration examples·····································································································································334
Configure RIPng basic functions ························································································································334
Configuring RIPng route redistribution ··············································································································337
OSPFv3 configuration············································································································································· 341
Introduction to OSPFv3················································································································································341
OSPFv3 overview ················································································································································341
OSPFv3 packets···················································································································································341
OSPFv3 LSA types···············································································································································342
Timers of OSPFv3 ················································································································································342
OSPFv3 features supported································································································································343
Protocols and standards ·····································································································································343
OSPFv3 configuration tasks ········································································································································343
Enabling OSPFv3 ················································································································································343
Enabling an OSPFv3 process·····························································································································344
Configuring OSPFv3 area parameters ·············································································································344
Configuring an OSPFv3 stub area ····················································································································344
Configuring an OSPFv3 virtual link···················································································································345
Configuring OSPFv3 network types···························································································································346
Configuring the OSPFv3 network type for an interface ··················································································346
Configuring an NBMA or P2MP neighbor·······································································································346
Configuring OSPFv3 routing information control ·····································································································347
Configuring OSPFv3 route summarization ·······································································································347
Configuring OSPFv3 inbound route filtering ····································································································348
Configuring an OSPFv3 cost for an interface ··································································································348
Configuring the maximum number of OSPFv3 load-balanced routes ···························································349
Configuring a priority for OSPFv3 ····················································································································349
Configuring OSPFv3 route redistribution··········································································································350
Tuning and optimizing OSPFv3 networks ·················································································································351
Configuring OSPFv3 timers································································································································351
Configuring a DR priority for an interface········································································································352
Ignoring MTU check for DD packets ·················································································································352
Disable interfaces from sending OSPFv3 packets ···························································································353

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Enable the logging of neighbor state changes ································································································353
Configuring OSPFv3 GR ·············································································································································354
Configuring GR Restarter····································································································································354
Configuring GR Helper·······································································································································354
Displaying and maintaining OSPFv3·························································································································355
OSPFv3 configuration examples ································································································································356
Configuring OSPFv3 areas ································································································································356
Configuring OSPFv3 DR election·······················································································································361
Configuring OSPFv3 route redistribution··········································································································364
Configuring OSPFv3 GR ····································································································································368
Troubleshooting OSPFv3 configuration ·····················································································································369
No OSPFv3 neighbor relationship established································································································369
Incorrect routing information ······························································································································370
IPv6 IS-IS configuration··········································································································································· 371
Introduction to IPv6 IS-IS··············································································································································371
Configuring IPv6 IS-IS basic functions························································································································371
Configuring IPv6 IS-IS routing information control ···································································································372
Prerequisites ·························································································································································372
Displaying and maintaining IPv6 IS-IS·······················································································································373
IPv6 IS-IS configuration example································································································································374
IPv6 BGP configuration··········································································································································· 377
IPv6 BGP overview·······················································································································································377
IPv6 BGP configuration tasks······································································································································377
Configuring IPv6 BGP basic functions ··············································································································377
Specifying an IPv6 BGP peer·····························································································································378
Injecting a local IPv6 route·································································································································378
Configuring a preferred value for routes from a peer or peer group····························································378
Specifying the source interface for establishing TCP connections ·································································379
Allowing the establishment of a non-direct eBGP connection ········································································380
Configuring a description for an IPv6 peer or peer group·············································································380
Disabling session establishment to an IPv6 peer or peer group ····································································381
Logging IPv6 peer or peer group state changes······························································································381
Controlling route distribution and reception ·············································································································381
Configuring IPv6 BGP route redistribution········································································································382
Advertising a default route to an IPv6 peer or peer group·············································································382
Configuring outbound route filtering·················································································································383
Configuring inbound route filtering ···················································································································383
Configuring IPv6 BGP and IGP route synchronization····················································································384
Configuring route dampening····························································································································385
Configuring IPv6 BGP route attributes ·······················································································································385
Configuring IPv6 BGP preference and default LOCAL_PREF and NEXT_HOP attributes ····························385
Configuring the MED attribute ···························································································································386
Configuring the AS_PATH attribute ···················································································································387

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Tuning and optimizing IPv6 BGP networks ···············································································································388
Configuring IPv6 BGP timers······························································································································388
Configuring IPv6 BGP soft reset·························································································································389
Enabling the IPv6 BGP ORF capability ·············································································································390
Configuring the maximum number of load-balanced routes ··········································································391
Configuring a large-scale IPv6 BGP network············································································································392
Configuring IPv6 BGP peer group·····················································································································392
Configuring IPv6 BGP community ·····················································································································394
Configuring an IPv6 BGP route reflector···········································································································394
Configuring 6PE ···························································································································································395
Configuring basic 6PE capabilities ···················································································································396
Configuring optional 6PE capabilities ··············································································································396
Displaying and maintaining IPv6 BGP·······················································································································398
Displaying BGP····················································································································································398
Resetting IPv6 BGP connections·························································································································399
Clearing IPv6 BGP information··························································································································400
IPv6 BGP configuration examples ······························································································································400
IPv6 BGP basic configuration ····························································································································401
IPv6 BGP route reflector configuration··············································································································403
Troubleshooting IPv6 BGP configuration ···················································································································405
No IPv6 BGP peer relationship established ·····································································································405
IPv6 unicast policy routing configuration ·············································································································· 406
Introduction to IPv6 unicast policy routing·················································································································406
Configuring IPv6 unicast policy routing·····················································································································406
Configuring IPv6 policy ······································································································································406
Configuring IPv6 local policy routing················································································································408
Configuring IPv6 interface policy routing·········································································································408
Displaying and maintaining IPv6 unicast policy routing configuration··································································409
IPv6 unicast policy routing configuration examples·································································································409
Configuring IPv6 local policy routing based on packet type ·········································································410
Configuring IPv6 interface policy routing based on packet type···································································412
Routing policy configuration ·································································································································· 415
Introduction to routing policy ······································································································································415
Routing policy and policy routing······················································································································415
Filters·····································································································································································415
Routing policy application··································································································································416
Routing policy configuration tasks······························································································································416
Defining filters······················································································································································416
Defining an IP-prefix list······································································································································417
Defining an AS-PATH list ····································································································································418
Defining a community list ···································································································································418
Defining an extended community list ················································································································419
Configuring a routing policy·······································································································································419

19
Creating a routing policy ···································································································································420
Defining if-match clauses ····································································································································420
Defining apply clauses········································································································································422
Defining a continue clause ·································································································································424
Displaying and maintaining the routing policy·········································································································425
Routing policy configuration examples······················································································································425
Applying a routing policy to IPv4 route redistribution·····················································································425
Applying a routing policy to IPv6 route redistribution·····················································································429
Applying a routing policy to filter received BGP routes··················································································431
Troubleshooting routing policy configuration ···········································································································433
IPv4 routing information filtering failure············································································································433
IPv6 routing information filtering failure············································································································434
Obtaining support for your product······················································································································· 436
Register your product···················································································································································436
Purchase value-added services ···································································································································436
Troubleshoot online······················································································································································436
Access software downloads········································································································································437
Telephone technical support and repair····················································································································437
Contact us ·····································································································································································437
Acronyms································································································································································· 438
Index ········································································································································································ 452

20
IP routing basics configuration
IP routing and routing table
Routing
Routing in the Internet is achieved through routers. Upon receiving a packet, a router finds an
optimal route based on the destination address and forwards the packet to the next router in the
path until the packet reaches the last router. The last router forwards the packet to the intended
destination host.
The term router in this document refers to both routers and Layer 3 switches.
Routing table
Routing tables play a key role in routing. Each router maintains a routing table. Each entry in the
table specifies which physical interface a packet destined for a certain destination will go out to
reach the next hop (the next router) or the directly connected destination.
Routes in a routing table can be divided into the following categories by origin:
•Direct routes: Routes discovered by data link protocols, also known as interface routes
•Static routes: Manually configured routes
•Dynamic routes: Routes discovered dynamically by routing protocols
Routing table contents
A routing table includes the following key items:
•Destination address: Destination IP address or destination network.
•Network mask: Specifies, in company with the destination address, the address of the
destination network. A logical AND operation between the destination address and the
network mask yields the address of the destination network. For example, if the destination
address is 129.102.8.10 and the mask is 255.255.0.0, then the address of the destination
network is 129.102.0.0. A network mask is made of a certain number of consecutive 1s. It
can be expressed in dotted decimal format or by the number of the 1s.
•Outbound interface: Specifies the interface through which the IP packets are to be
forwarded.
•IP address of the next hop: Specifies the address of the next router on the path. If only the
outbound interface is configured, its address will be the IP address of the next hop.