Cisco Nexus 7000 Series User manual

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Cisco Nexus 7000 Series NX-OS Unicast
Routing Configuration Guide, Release 4.x
April 18, 2011
Text Part Number: OL-20002-02

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Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x
©2008–2009 Cisco Systems, Inc. All rights reserved.

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Cisco Nexus 7000 Series NX-OS Unicast Routing Configuration Guide, Release 4.x
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CONTENTS
New and Changed Information i
Preface iii
Audience iii
Organization iii
Document Conventions iv
Related Documentation v
Obtaining Documentation and Submitting a Service Request vi
CHAPTER 1Overview 1-1
Information About Layer 3 Unicast Routing 1-1
Routing Fundamentals 1-2
Packet Switching 1-2
Routing Metrics 1-3
Path Length 1-4
Reliability 1-4
Routing Delay 1-4
Bandwidth 1-4
Load 1-4
Communication Cost 1-4
Router IDs 1-5
Autonomous Systems 1-5
Convergence 1-6
Load Balancing and Equal Cost Multipath 1-6
Route Redistribution 1-6
Administrative Distance 1-7
Stub Routing 1-7
Routing Algorithms 1-8
Static Routes and Dynamic Routing Protocols 1-8
Interior and Exterior Gateway Protocols 1-8
Distance Vector Protocols 1-9
Link-State Protocols 1-9
Layer 3 Virtualization 1-10
Cisco NX-OS Fowarding Architecture 1-10

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Unicast RIB 1-11
Adjacency Manager 1-11
Unicast Forwarding Distribution Module 1-12
FIB 1-12
Hardware Forwarding 1-12
Software Forwarding 1-12
Summary of Layer 3 Unicast Routing Features 1-13
IPv4 and IPv6 1-13
IP Services 1-13
OSPF 1-13
EIGRP 1-14
IS-IS 1-14
BGP 1-14
RIP 1-14
Static Routing 1-14
Layer 3 Virtualization 1-15
Route Policy Manager 1-15
Policy-Based Routing 1-15
First-Hop Redundancy Protocols 1-15
Object Tracking 1-15
Related Topics 1-15
IP
CHAPTER 2Configuring IPv4 2-1
Information About IPv4 2-1
Multiple IPv4 Addresses 2-2
Address Resolution Protocol 2-2
ARP Caching 2-3
Static and Dynamic Entries in the ARP Cache 2-3
Devices that do not use ARP 2-4
Reverse ARP 2-4
Proxy ARP 2-5
Local Proxy ARP 2-5
Gratuitous ARP 2-5
ICMP 2-5
Virtualization Support 2-6
Licensing Requirements for IPv4 2-6
Prerequisites for IPv4 2-6

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Guidelines and Limitations 2-6
Configuring IPv4 2-6
Configuring IPv4 Addressing 2-7
Configuring Multiple IP Addresses 2-8
Configuring a Static ARP Entry 2-9
Configuring Proxy ARP 2-10
Configuring Local Proxy ARP 2-11
Configuring Gratuitous ARP 2-12
Configuring IP Packet Verification 2-13
Configuring IP Directed Broadcasts 2-14
Verifying the IPv4 Configuration 2-15
IPv4 Example Configuration 2-15
Default Settings 2-15
Additional References 2-15
Related Documents 2-16
Standards 2-16
Feature History for IP 2-16
CHAPTER 3Configuring IPv6 3-1
Information About IPv6 3-1
IPv6 Address Formats 3-2
IPv6 Unicast Addresses 3-3
Aggregatable Global Addresses 3-3
Link-Local Addresses 3-5
IPv4-Compatible IPv6 Addresses 3-5
Unique Local Addresses 3-6
Site-Local Address 3-7
IPv6 Anycast Addresses 3-7
IPv6 Multicast Addresses 3-7
IPv4 Packet Header 3-9
Simplified IPv6 Packet Header 3-9
DNS for IPv6 3-12
Path MTU Discovery for IPv6 3-12
CDP IPv6 Address Support 3-12
ICMP for IPv6 3-12
IPv6 Neighbor Discovery 3-13
IPv6 Neighbor Solicitation Message 3-13
IPv6 Router Advertisement Message 3-15
IPv6 Neighbor Redirect Message 3-16

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Virtualization Support 3-17
Licensing Requirements for IPv6 3-18
Prerequisites for IPv6 3-18
Guidelines and Limitations for IPv6 3-18
Configuring IPv6 3-18
Configuring IPv6 Addressing 3-19
Configuring IPv6 Neighbor Discovery 3-20
Optional IPv6 Neighbor Discovery 3-22
Configuring IPv6 Packet Verification 3-23
Verifying the IPv6 Configuration 3-24
IPv6 Example Configuration 3-24
Default Settings 3-24
Additional References 3-24
Related Documents 3-25
Standards 3-25
Feature History for IPv6 3-25
CHAPTER 4Configuring DNS 4-1
Information About DNS Clients 4-1
DNS Client Overview 4-1
Name Servers 4-2
DNS Operation 4-2
High Availability 4-2
Virtualization Support 4-2
Licensing Requirements for DNS Clients 4-2
Prerequisites for DNS Clients 4-3
Configuration Guidelines and Limitations 4-3
Configuring DNS Clients 4-3
Configuring the DNS Client 4-3
Configuring Virtualization 4-5
Verifying the DNS Client Configuration 4-7
DNS Client Example Configuration 4-7
Default Settings 4-7
Additional References 4-8
Related Documents 4-8
Standards 4-8
Feature History for DNS 4-8

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CHAPTER 5Configuring WCCPv2 5-1
Information About WCCPv2 5-1
WCCPv2 Overview 5-2
WCCPv2 Service Types 5-2
Service Groups 5-2
Service Group Lists 5-3
WCCPv2 Designated Cache Engine 5-4
Redirection 5-4
WCCPv2 Authentication 5-5
Redirection Method 5-5
Packet Return Method 5-5
High Availability for WCCPv2 5-6
Virtualization Support for WCCPv2 5-6
Licensing Requirements for WCCPv2 5-6
Prerequisites for WCCPv2 5-6
Guidelines and Limitations for WCCPv2 5-6
Configuring WCCPv2 5-7
Enabling the WCCPv2 Feature 5-7
Configuring a WCCPv2 Service Group 5-8
Applying WCCPv2 Redirection to an Interface 5-9
Configuring WCCPv2 in a VRF 5-10
Verifying WCCPv2 Configuration 5-12
WCCPv2 Example Configuration 5-12
Default Settings 5-13
Additional References 5-13
Related Documents 5-13
Standards 5-13
Feature History for WCCPv2 5-13
Routing
CHAPTER 6Configuring OSPFv2 6-1
Information About OSPFv2 6-1
Hello Packet 6-2
Neighbors 6-2
Adjacency 6-3
Designated Routers 6-3
Areas 6-4

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Link-State Advertisements 6-5
LSA Types 6-5
Link Cost 6-6
Flooding and LSA Group Pacing 6-6
Link-State Database 6-7
Opaque LSAs 6-7
OSPFv2 and the Unicast RIB 6-7
Authentication 6-7
Simple Password Authentication 6-8
MD5 Authentication 6-8
Advanced Features 6-8
Stub Area 6-8
Not-So-Stubby Area 6-9
Virtual Links 6-9
Route Redistribution 6-10
Route Summarization 6-10
High Availability and Graceful Restart 6-11
OSPFv2 Stub Router Advertisements 6-12
Multiple OSPFv2 Instances 6-12
SPF Optimization 6-12
Virtualization Support 6-12
Licensing Requirements for OSPFv2 6-12
Prerequisites for OSPFv2 6-13
Configuration Guidelines and Limitations 6-13
Configuring Basic OSPFv2 6-13
Enabling the OSPFv2 Feature 6-14
Creating an OSPFv2 Instance 6-15
Configuring Optional Parameters on an OSPFv2 Instance 6-16
Configuring Networks in OSPFv2 6-17
Configuring Authentication for an Area 6-19
Configuring Authentication for an Interface 6-21
Configuring Advanced OSPFv2 6-23
Configuring Filter Lists for Border Routers 6-23
Configuring Stub Areas 6-25
Configuring a Totally Stubby Area 6-26
Configuring NSSA 6-27
Configuring Virtual Links 6-29
Configuring Redistribution 6-31
Limiting the Number of Redistributed Routes 6-33

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Configuring Route Summarization 6-35
Configuring Stub Route Advertisements 6-36
Modifying the Default Timers 6-37
Configuring Graceful Restart 6-40
Restarting an OSPFv2 Instance 6-41
Configuring OSPFv2 with Virtualization 6-42
Verifying the OSPFv2 Configuration 6-44
Displaying OSPFv2 Statistics 6-45
OSPFv2 Example Configuration 6-45
Default Settings 6-45
Additional References 6-46
Related Documents 6-47
MIBs 6-47
Feature History for OSPFv2 6-47
CHAPTER 7Configuring OSPFv3 7-1
Information About OSPFv3 7-1
Comparison of OSPFv3 and OSPFv2 7-2
Hello Packet 7-2
Neighbors 7-3
Adjacency 7-3
Designated Routers 7-4
Areas 7-5
Link-State Advertisement 7-5
LSA Types 7-6
Link Cost 7-6
Flooding and LSA Group Pacing 7-7
Link-State Database 7-7
Multi-Area Adjacency 7-7
OSPFv3 and the IPv6 Unicast RIB 7-8
Address Family Support 7-8
Advanced Features 7-8
Stub Area 7-9
Not-So-Stubby Area 7-9
Virtual Links 7-10
Route Redistribution 7-10
Route Summarization 7-10
High Availability and Graceful Restart 7-11
Multiple OSPFv3 Instances 7-12

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Contents
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SPF Optimization 7-12
Virtualization Support 7-12
Licensing Requirements for OSPFv3 7-12
Prerequisites for OSPFv3 7-12
Configuration Guidelines and Limitations 7-13
Configuring Basic OSPFv3 7-13
Enabling the OSPFv3 Feature 7-13
Creating an OSPFv3 Instance 7-14
Configuring Networks in OSPFv3 7-17
Configuring Advanced OSPFv3 7-19
Configuring Filter Lists for Border Routers 7-20
Configuring Stub Areas 7-21
Configuring a Totally Stubby Area 7-22
Configuring NSSA 7-23
Configuring Multi-Area Adjacency 7-25
Configuring Virtual Links 7-26
Configuring Redistribution 7-28
Limiting the Number of Redistributed Routes 7-30
Configuring Route Summarization 7-32
Modifying the Default Timers 7-34
Configuring Graceful Restart 7-36
Restarting an OSPFv3 Instance 7-37
Configuring OSPFv3 with Virtualization 7-38
Verifying OSPFv3 Configuration 7-40
Displaying OSPFv3 Statistics 7-40
OSPFv3 Example Configuration 7-41
Related Topics 7-41
Default Settings 7-41
Additional References 7-42
Related Documents 7-43
MIBs 7-43
Feature History for OSPFv3 7-43
CHAPTER 8Configuring EIGRP 8-1
Information About EIGRP 8-1
EIGRP Components 8-2
Reliable Transport Protocol 8-2
Neighbor Discovery and Recovery 8-2